# NAD in Transit !!! I`m hypped



## Frenchy99 (Oct 15, 2016)

I saw this posted 2 weeks ago and went for it !!!

Here is the rarest and most powerful Garnet of them all... The Pro 600 Super !!! 

This baby is rated at 225 Watts with 6... yep ! 6 EL34 in the power section 

Based on the info, only a handful of these were made... so quite scarce...

This baby left Edmonton yesterday , direction Montreal... should get it next Friday ... Hopefully !

Here are some of the sellers pics !


Look at the size of these transformers !!!


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## cboutilier (Jan 12, 2016)

That is super cool.


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## Frenchy99 (Oct 15, 2016)

This baby hasn't worked for the last 25 years and was left stored in a garage... A power tube blew and took out most of all the screen resistors and burnet some wires with it... So , some repairs are to be done once it arrives... 

Gut shoots.


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## Frenchy99 (Oct 15, 2016)

All the original tubes are included by the way... I have an old but amazing tube tester here to go thru them all... will at least save 4 to 5 original Garnet branded 6CA7 mullard tubes...

Retubing this baby will be expensive !


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## cboutilier (Jan 12, 2016)

I'm excited for you


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## Budda (May 29, 2007)

Frenchy99 said:


> All the original tubes are included by the way... I have an old but amazing tube tester here to go thru them all... will at least save 4 to 5 original Garnet branded 6CA7 mullard tubes...
> 
> Retubing this baby will be expensive !


It will, but imagine if it was 4 KT88's .

Man i wanna try that thing.


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## Frenchy99 (Oct 15, 2016)

The seller was great to deal with... He took great care and put lots of work and effort to make certain that this baby would get here in one piece. He built this for the transport...


This baby weight in at a whooping 69 Lbs !!!


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## Frenchy99 (Oct 15, 2016)

cboutilier said:


> I'm excited for you



You have no Idea !!! 

I even told the wife I bought it so much I was excited !!!


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## Frenchy99 (Oct 15, 2016)

Budda said:


> It will, but imagine if it was 4 KT88's .


6 !!! 6 power tubes !!! HNG^%$



Budda said:


> Man i wanna try that thing.


That s enough Power to push you off stage !!!


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## ezcomes (Jul 28, 2008)

looking at the pictures...the head shell is the rigt way up...and so is the amp chasis...so...is the headshell not original?

i can't even fathom the headroom and shear destruction that could envelop...way cool!


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## KapnKrunch (Jul 13, 2016)

Lord have mercy!

What a great packing job! 

I don't need to know where Rock City is to visit. Just crank 'er. I'll hear it from here.


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## Frenchy99 (Oct 15, 2016)

ezcomes said:


> looking at the pictures...the head shell is the rigt way up...and so is the amp chasis...so...is the headshell not original?


He just removed the front to take out the chassis and put it back in without screwing it to the top. The chassis sits on the bottom and the panel with Garnet goes ontop. " screws holds it. sometimes its easier to remove the front since its a real tight fit on the chassis. Its all original... but I will most likely re tolex the thing...



ezcomes said:


> i can't even fathom the headroom and shear destruction that could envelop...way cool!



This will be used as a bass head  Who needs an SVT....

Cant wait to take it outside and direct it towards my pestering neighbor !!! HNG^%$


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## Frenchy99 (Oct 15, 2016)

KapnKrunch said:


> Lord have mercy!
> 
> What a great packing job!


I know!

Best I`ve seen... Great respect for the seller...




KapnKrunch said:


> I don't need to know where Rock City is to visit. Just crank 'er. I'll hear it from here.


You`ll be hearing me very soon !!! 
HNG^%$


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## TheYanChamp (Mar 6, 2009)

I do love me some tranny porn!

Please tell me you'll get a couple 6x12's and crank her.. er.. crank it.


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## sulphur (Jun 2, 2011)

Wow, that some serious iron. Congrats!


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## mhammer (Nov 30, 2007)

cboutilier said:


> That is super cool.


I don't know. With all those tubes, Frenchy may need to run it in a room that always has good ventilation or even always-on AC.


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## Budda (May 29, 2007)

Frenchy99 said:


> That s enough Power to push you off stage !!!


Come catch a show and you'll hear why I want it haha.


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## Frenchy99 (Oct 15, 2016)

TheYanChamp said:


> I do love me some tranny porn!
> 
> Please tell me you'll get a couple 6x12's and crank her.. er.. crank it.


It took me 25 years to find a BTO-L cab in the Montréal area. Can you imagine 2 6X12 BTO cabs!!!


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## cboutilier (Jan 12, 2016)

mhammer said:


> I don't know. With all those tubes, Frenchy may need to run it in a room that always has good ventilation or even always-on AC.


I have a love for the impractical. I've always wanted a Super Six Reverb...


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## Lincoln (Jun 2, 2008)

Wow! What a cool find! Congrats. Good to see it go to someone who appreciates what it is. I had never even seen mention of a 600 Super before.
No idea what you're going to do with 225 watts of power, but.......Oh baby!!!


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## Adcandour (Apr 21, 2013)

I love that font. Something about it...


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## Frenchy99 (Oct 15, 2016)

Lincoln said:


> No idea what you're going to do with 225 watts of power, but.......Oh baby!!!


Easy and simple enough... I`ll just go jam with Budda !!! HNG^%$


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## Granny Gremlin (Jun 3, 2016)

Holy shit Jealous. ... and here I sold my Sessionman for a Sunn 1200s cuz I need more power/headroom.

Great score. Congrats. Those Garnet/Mullard 6CA7s in that circuit (essentially same as my Sessionman, but x3) crunch so nice.


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## Budda (May 29, 2007)

Frenchy99 said:


> Easy and simple enough... I`ll just go jam with Budda !!! HNG^%$


Excellent haha.


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## Frenchy99 (Oct 15, 2016)

Granny Gremlin said:


> Great score. Congrats. Those Garnet/Mullard 6CA7s in that circuit (essentially same as my Sessionman, but x3) crunch so nice.


Thanks!

Never imagined I`d find one so when one showed up for sale in Edmonton, contacted the seller right away. I wasn't the first to contact him but I wanted it... I`m the only guy that was willing to pay the shipping I guess... The shipping charges are a B.... but don't think I`d get another chance at one.


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## Granny Gremlin (Jun 3, 2016)

Frenchy99 said:


> Thanks!
> 
> Never imagined I`d find one so when one showed up for sale in Edmonton, contacted the seller right away. I wasn't the first to contact him but I wanted it... I`m the only guy that was willing to pay the shipping I guess... The shipping charges are a B.... but don't think I`d get another chance at one.


Agreed - Never seen one IRL


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## Frenchy99 (Oct 15, 2016)

Hey GG, would you mind looking in your Garnet book to see if a schematic exist for the LB600S ?

I cant seem to find anything online...


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## Morkolo (Dec 9, 2010)




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## Granny Gremlin (Jun 3, 2016)

Frenchy99 said:


> Hey GG, would you mind looking in your Garnet book to see if a schematic exist for the LB600S ?
> 
> I cant seem to find anything online...


It'll be the same as a later era Pro 200 or 400 but more power tubes and bigger iron. I'll have a look.



Morkolo said:


>


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## Sneaky (Feb 14, 2006)




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## High/Deaf (Aug 19, 2009)

You must be happy that Quebec has some of the cheapest electricity prices in NA. Otherwise, that could be expensive.


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## Frenchy99 (Oct 15, 2016)

Granny Gremlin said:


> It'll be the same as a later era Pro 200 or 400 but more power tubes and bigger iron. I'll have a look.



Thanks GG but I got one !!!

Larry from Red Rock Amps was kind enough to send me one... That guy knows his Garnet`s !


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## Frenchy99 (Oct 15, 2016)

High/Deaf said:


> You must be happy that Quebec has some of the cheapest electricity prices in NA. Otherwise, that could be expensive.



Tell me about it !  With the continuous record lows ( -40 ) since the beg of Dec here in Québec, my last Hydro bill was double what its suppose to be !!!

I`ll just heat the house with the amp !!!


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## keithb7 (Dec 28, 2006)

I recently worked on one like yours Frenchy. Similar layout and design. I am not sure on the wattage of this one. Sounded very good though!


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## Granny Gremlin (Jun 3, 2016)

That's roughly equivalent to the Pro 400; bit over a 100 watts (which does correlate with Gar's tendency to use peak vs RMS wattage, rounded to the nearest convenient number, as the model name - 200 as on that United is double 100 which is about right). There's no way the 600 is 225 by the way; at least 150 but def at least a tad south of 200. And yes, half of 600 is 300, but don't forget the 'nearest convenient number ' bit. Since there was already a Pro 200 model, and a 400 (why the heck he didn't call it the 300 I dunno; some people just like even numbers I guess and also marketting) so this one had to go to 600; double the tubes so double the model number. And that's after the Sesionman was given the G100 - sometimes G90 - model number (shot himself in the foot by changing it from 90 to 100) so the Pro had to go higher to start with and it's a bit steaming mess of confusion.

Forgetting the model numbers, which are less reliable (as peak wattage indicators) the later the era and bigger the amp, Garnet variously classified 2 x 6CA7 amps as 50, 60 or 75 watts RMS, adding a second (or third) pair cannot be more than double (or triple) that (already inflated - there's no way my old Sessionman was 75 watts) rating (Gar himself disagreed with himself - the website says 75, as does some other product lit I have seen, but the Garnet book says 60). Also just about every other EL34 amp ever made called it 50 per pair (which is rounding to a nice whole number, I know). Depending on which specific model (Pro, SMan or BTO) and era, the plate voltage was spec'd (we know that isn't always perfectly accurate, but close enough for this estimate) 505-515V; which in class AB1 is about 50 per pair, probably a hair more, plus preamp gain (Gar did include that in his ratings) so I think 60 is fair. There were some esoteric amps out there claiming to reach almost 200 watts with a quad of EL34s, but I dunno what plate voltage they were running at (on paper the max is 800) and I have no experience with them. The max possible output of a pair of EL34s is given as 70 on the spec sheet tho (so +5 for preamp gain is likely where the 75W thing came from) but that's if you push the snot outa them.


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## Frenchy99 (Oct 15, 2016)

keithb7 said:


> I recently worked on one like yours Frenchy. Similar layout and design. I am not sure on the wattage of this one. Sounded very good though!



Nice !!!

That's the stencil version of the Pro 200 with 2 power tubes... based on Garnet specs, 75 Watts. based on tube ratings... 50Watts...


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## Granny Gremlin (Jun 3, 2016)

Shit, you're right - Pro 200 not 400. Thought I saw 4 power tube sockets but only 2 are used the others are chassis cutout fillers.


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## Frenchy99 (Oct 15, 2016)

Granny Gremlin said:


> Also just about every other EL34 amp ever made called it 50 per pair (which is rounding to a nice whole number, I know). Depending on which specific model (Pro, SMan or BTO) and era, the plate voltage was spec'd (we know that isn't always perfectly accurate, but close enough for this estimate) 505-515V; which in class AB1 is about 50 per pair



Still trying to figure out the 90Watts from the Traynor YBA-1A with 2 EL34`s in the power section....



Granny Gremlin said:


> The max possible output of a pair of EL34s is given as 70 on the spec sheet tho (so +5 for preamp gain is likely where the 75W thing came from) but that's if you push the snot outa them.


That explains lots... Like I previously mentioned, I also have Dynacord Gigant amp with 4 EL34 in the power section running 700+ volts , they rate it a 150 Watts....
( amazing head for bass by the way...HNG^%$)


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## Frenchy99 (Oct 15, 2016)

Granny Gremlin said:


> Shit, you're right - Pro 200 not 400. Thought I saw 4 power tube sockets but only 2 are used the others are chassis cutout fillers.


Same chassis for both... easy to miss from underneath...


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## jb welder (Sep 14, 2010)

Frenchy99 said:


> Still trying to figure out the 90Watts from the Traynor YBA-1A with 2 EL34`s in the power section....


It's not about the tubes it's about the iron. They're called 'valves' for a reason. And they act as valves between the power supply and the OT.
The max. wattage spec. is what the plate of the tube can safely dissipate internally, not what it can pass on to it's load.
Lot's of guys will swear up and down the 90W spec. for the YBA-1A is impossible. None of those guys have ever bothered to try measuring one.


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## Frenchy99 (Oct 15, 2016)

Lot's of guys will swear up and down the 90W spec. for the YBA-1A is impossible. None of those guys have ever bothered to try measuring one.[/QUOTE]

I don't know enough about tube amps to get full technical about plate dissapation and such but I do know that 45 watts from Traynor equals almost 80 watts from other company's. ... I know both Garnet and Traynor larger amps put out huge sound. They both use massive iron on large models. 

Wattage ratings are not equal from one company to another.


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## Lincoln (Jun 2, 2008)

I had a 2 x EL34 PA that was rated at 65 watts. Massive iron on that one too. My Pro 200 drowned out a lot of Fender Bassman's back in the day. Pretty sure it's more than 50 watts.
Filter caps on a Pro 200 are set up for 700 volts. I bet your super 600 is set up to handle even higher volts. I'd like to see a schematic on it


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## Budda (May 29, 2007)

Now I want bigger iron when mine dies.


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## bolero (Oct 11, 2006)

wow that is a monster allright

congratulations!!


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## Frenchy99 (Oct 15, 2016)

Budda said:


> Now I want bigger iron when mine dies.


Its a must ! ! !


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## Frenchy99 (Oct 15, 2016)

Lincoln said:


> I'd like to see a schematic on it


Had to work out how to retreive it from a closed off PDF but here is what I managed to salvage.


The pre...


Power section...


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## Lincoln (Jun 2, 2008)

I see now there is mention of and a pre-amp schematic for the LB600S (Pro Super Series) in Gar's book. Nothing for the power amp/power supply section though.
edit:
ha, ha, we must have been looking in the book at the same time


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## Frenchy99 (Oct 15, 2016)

Lincoln said:


> Nothing for the power amp/power supply section though.


I know !

Real lucky that Larry was there to help me out with the schematics... 

I`d rather have a schematic to work off then try to guesswork ! ...


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## Frenchy99 (Oct 15, 2016)

The Eagle has Landed !!!


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## Lincoln (Jun 2, 2008)

Frenchy99 said:


> The Eagle has Landed !!!


did you warn the neighbors in advance?

I guess they'll know soon enough. Why spoil the surprise, right?


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## Frenchy99 (Oct 15, 2016)

OK, here are the arrival pics !!!


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## Frenchy99 (Oct 15, 2016)

The first thing I did is pull the tubes...

The 5 original tubes ( I think they are all the same, 2 Garnets and 3 General electric all Made in Japan) test perfect at 80%... The Roger 6CA7 tube was leaking at pin 3.... so, one bad tube... Preamps all original and all good !

More test to be done today on it !


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## Granny Gremlin (Jun 3, 2016)

Man, the only thing keeping the jealousy at bay is that these didn't have reverb.


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## Budda (May 29, 2007)

Dibs.


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## cboutilier (Jan 12, 2016)

Budda said:


> Dibs.


I call sloppy seconds.


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## Lincoln (Jun 2, 2008)

There's a Garnet treble clef for sale on eBay right now. It would look real nice on the right front of that amp.

Vintage Garnet Treble Clef Amplifier Badge | eBay


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## Frenchy99 (Oct 15, 2016)

Since I bought this amp knowing that repairs were needed , my biggest worry was the Output transformer. I took my readings on the primary, that looked OK. Took a look at the secondary, seemed fine. No continuity between the 2, OK.

Mind you, I only have a cheap Canadian Tire meter so don't really trust the results.

Since I was still uncertain on the OT ... did lots and lots of research on the internet on how to test it... yes my meter gave me correct numbers but.... before going forward I wanted more reassurance.

So, I finally fell on a stupid an easy 9V battery test.... Since we can test speakers with a 9V battery to make certain the coil is still good, so can you verify if signal goes to the speaker true the OT with a 9V battery !







You connect one lead of the battery to the Primary red wire of the transformer and the second lead to pin 3 of any tube socket (no tubes in it)... You get sound/scratchiness in the speaker, You're good to go !!!























This Baby will Rock again soon !!! HNG^%$


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## Robert1950 (Jan 21, 2006)

When you get it up and running, set it up outside and crank it a midnight.


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## Frenchy99 (Oct 15, 2016)

Robert1950 said:


> When you get it up and running, set it up outside and crank it a midnight.


2 Minutes to Midnight !!! HNG^%$


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## greco (Jul 15, 2007)

Frenchy99 said:


> So, I finally fell on a stupid an easy 9V battery test.... Since we can test speakers with a 9V battery to make certain the coil is still good, so can you verify if signal goes to the speaker true the OT with a 9V battery !
> 
> 
> 
> ...


Very interesting. Can you explain this from an electronics perspective? Thanks.


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## Frenchy99 (Oct 15, 2016)

greco said:


> Very interesting. Can you explain this from an electronics perspective? Thanks.


Ouff... I don't think I'm qualified to answer that...

Been basically taking amp repair courses on the internet for the last couple of months to understand the principle. For the output transformer, not much was available except measuring the resistance's on the Primary , on the secondary and then see if there is continuity between the two.


An output transformer has 2 core winding, the Primary side that comes from the output tubes and comes out on the second winding for you ohms tabs, any of these 2 windings get damage or burned. the transformer is dead...


This diagram shows the primary ( Left side ) the middle red lead is the center tab and the bleu and brown leads connect to the tube from each side of the push pull amp (guitar amp) red to brown has to measure in resistance almost the same to red and bleu. bleu and brown the sum of both to verify that the core winding on the primary side is not burnt.

On the secondary side ( Right side ), you have the outputs, 16-8-4 ohms... black is neutral. You can then verify the resistance on each. black to green will be higher then black to yellow..ect...

You then verify red center tab to transformer casing if continuity, red center primary tab to any of the secondary side for continuity... if any continuity, the transformer is bad.... 

But even if all your numbers are correct, this does not mean you have a good transformer... this is what left me perplexed... to verify in depth, you need a ton of equipment that the normal man wont have... wave generator, oscilloscopes ect...

I finally found on an antique radio site this 9V battery test. The guy wrote that an easy way to determine if he was going to even waste his time at restoring it , the output 9V battery test needed to done foremost...


So .... by putting a small voltage current ( 9 volt battery ) on the red center tab and on one of the brown or bleu wires on the primary side ( both the brown and bleu wires are connected to pin 3 of the output tube channel, bleu on one side , brown on the second side) if this voltage current goes thru the generator and gives you sound on your speaker ( a cab or speaker needs to be connected for this test) then basically, the output transformer cores ( both windings ) are not damaged or burnt...

This test would have been easier and quicker to do in the first place to determine if the transformer could generate sound.

This is the best explanation I can provide with my limited knowledge on the subject.


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## greco (Jul 15, 2007)

Frenchy99 said:


> So .... by putting a small voltage current ( 9 volt battery ) on the red center tab and on one of the brown or bleu wires on the primary side ( both the brown and bleu wires are connected to pin 3 of the output tube channel, bleu on one side , brown on the second side) if this voltage current goes thru the generator and gives you sound on your speaker ( a cab or speaker needs to be connected for this test) then basically, the output transformer cores ( both windings ) are not damaged or burnt...


You wrote an excellent explanation. Thank you for taking the time to respond to my question.

_"( both the brown and bleu wires are connected to pin 3 of the output tube channel, bleu on one side , brown on the second side)"_

I wasn't aware of this. That makes it simple to understand.

I didn't know that direct current (DC) would "pass through" a transformer. 
I have always associated transformers with stepping up (or stepping down) alternating current (AC). I also didn't know that a speaker would produce sound when a DC current was used to drive it. 

I have used 4 VAC with a tiny current to drive a guitar speaker to get the 60 cycle hum for "breaking in" a new speaker (However, in the end, I'm not sure if it really does anything for the new speaker ...LOL)

To get sound from the speaker did you have to make and break the battery connection ? Was it a crackling/scratchy sound?

Thanks again.

Cheers

Dave


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## cboutilier (Jan 12, 2016)

greco said:


> You wrote an excellent explanation. Thank you for taking the time to respond to my question.
> 
> _"( both the brown and bleu wires are connected to pin 3 of the output tube channel, bleu on one side , brown on the second side)"_
> 
> ...


Hitting a speaker with DC will make it make one sound.


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## Granny Gremlin (Jun 3, 2016)

cboutilier said:


> Hitting a speaker with DC will make it make one sound.


Yes, you can use a 9 volt battery to test a speaker for continuity (a multimeter is better, but if in a pinch) and it is the best easy way to test a speaker for polarity (which terminal is +).

However, a sustained DC voltage can kill the speaker. In both cases (testing speaker or OT) *make sure to only connect the battery momentarily*.

The OT test is essentially the same as the speaker test except you have the OT in front of the speaker to see if allows the signal through. Note, this may not expose a shorted winding, but it will tell you if there is an open winding (as will just taking the DCR of each winding) because there will be no signal (or infinite resistance using a MM). Just like you'd test a pickup.

You can do this test and still have a shorted winding, which would result in the turns ratio (e.g. as in the diagrams above ) being compromised or changed (so that 9 watts at 6.4k sending 240 V 0.0375A to the primary no longer becomes 12V 0.75A @16Ohms on the other side) which can cause the OT and/or power tubes to work too hard/heat up/burn out (not right away usually, but sometimes in rather short order). The only way around that (improve the test to be sure of a short) is to do the math and figure out what 9V should become on the other side and measure it to see if that's what you get (give or take within reason). Generally that's better done with a sustained sine wave (AC) vs a DC battery sending a momentary pulse.


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## cboutilier (Jan 12, 2016)

Granny Gremlin said:


> Yes, you can use a 9 volt battery to test a speaker for continuity (a multimeter is better, but if in a pinch) and it is the best easy way to test a speaker for polarity (which terminal is +).
> 
> However, a sustained DC voltage can kill the speaker. In both cases (testing speaker or OT) make sure to only connect the battery momentarily.


Its a great way to cook a car audio subwoofer just before the warranty runs out.


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## jb welder (Sep 14, 2010)

greco said:


> I didn't know that direct current (DC) would "pass through" a transformer.
> I have always associated transformers with stepping up (or stepping down) alternating current (AC). I also didn't know that a speaker would produce sound when a DC current was used to drive it.


It's not the DC passing, it's the pulse. A coil or transformer reacts to a change in current through the winding. When you connect the DC there is a sudden change in current, also when you disconnect. While it is connected, there is no change in current, so nothing happens.
If you worked on cars you may remember ignition points. They applied a DC pulse to the coil. That's when the spark would occur. If the points stayed open or closed it would not keep sparking.
The battery OT test is a nice 'quick & dirty' simple test that checks for gross faults like Granny said. It won't tell you if the OT breaks down at high voltage like we have in tube amps. But it will expose the most common faults like open winding or badly burnt shorted winding.
It's an easy variation of the neon bulb test that is another way of checking transformers.

With the battery direct to a speaker it's a similar scenario. As the battery connects you hear a pop. This is the change in current. Then the DC will hold the cone one direction but make no sound as the current is not changing. Disconnecting the battery you hear another thump as the cone returns to it's resting position.


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## cboutilier (Jan 12, 2016)

jb welder said:


> It's not the DC passing, it's the pulse. A coil or transformer reacts to a change in current through the winding. When you connect the DC there is a sudden change in current, also when you disconnect. While it is connected, there is no change in current, so nothing happens.
> If you worked on cars you may remember ignition points. They applied a DC pulse to the coil. That's when the spark would occur. If the points stayed open or closed it would not keep sparking.
> The battery OT test is a nice 'quick & dirty' simple test that checks for gross faults like Granny said. It won't tell you if the OT breaks down at high voltage like we have in tube amps. But it will expose the most common faults like open winding or badly burnt shorted winding.
> It's an easy variation of the neon bulb test that is another way of checking transformers.
> ...


Connecting a speaker to 115V AC will also make one singular thump, and then smoke.


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## greco (Jul 15, 2007)

@Granny Gremlin and @jb welder 

Thanks for all of your clarification and teaching. Very thoughtful of you to take the time.


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## greco (Jul 15, 2007)

jb welder said:


> It's an easy variation of the neon bulb test that is another way of checking transformers.


I found this to educate myself and thought others might enjoy reading it, especially the OP.

*The Super-Secret Transformer Tester*
R.G. Keen
March 15, 2007
This month I thought I’d give you amp techs a tip that is not widely known at all: it is not only possible, but easy, to test a transformer for internal shorts that are not otherwise detectable. Before you go and replace an expensive transformer, you need to try this.

Any of us who have worked on transformers are familiar with how you test for opens on the windings and shorts from winding to winding. You get out your ohm-meter and start measuring resistance. Opens where there is supposed to be resistance or resistance where there is supposed to be an open are dead giveaways. But what if there is one turn shorted down deep in the middle of a winding? The resistance testing will never pick that up – it’s not a big enough change in resistance.

Here’s how to tell if there’s an internal short. First, as always, unplug the amp for safety. If we disconnect all the windings of a transformer and then apply a DC voltage to only one winding, the iron core thinks it’s just an inductor. The voltage causes a current to flow in the inductor.

When you open the circuit, the magnetic field stored in the iron core creates a voltage on the winding to try to keep the current flowing – well-known inductor kickback.

All of the windings on the transformer are also magnetically coupled to the iron, and a proportional voltage appears on every one of them. If we connect a common neon lamp like the venerable NE-2 bulb to any winding and load up any winding with DC, when we open the DC loop, the voltage on all windings will increase until something conducts current. If all of the windings are open (as they should be), the NE-2 lamp will break over and flash when the voltage across it hits 75-90V.

But if there is a shorted turn inside the transformer, the iron’s stored magnetism will be entirely spent on trying to make the current keep flowing in that turn of wire. The neon light will not flash.







A simple setup for this is shown in the illustration: a DC supply, a neon bulb plus a resistor (to keep from burning out the neon) and some wire clips. I use a 6V lantern battery, but any DC supply will work as long as it will not be damaged by being connected to a low-resistance transformer winding. A current-limited bench supply works fine. I think a 9V battery or a D cell might work too, but I haven’t tried them.

First, make sure there are no loads on any winding. Then clip the neon and resistor across any winding. Touch your DC source to any winding, and then open it. Watch the lamp. If it flashes, there is no internal or external short. If it does not flash, there is a short. It’s that easy.

Keep in mind there are a few sneaky things that can invalidate your test. If there is a load on any winding, those loads will eat the inductive kickback and the neon will not light up. You’ll think you have a bad transformer but you might not. If the transformer is a power transformer, watch out for connections to filament windings or solidstate rectifiers. If it’s an output transformer, make sure the speaker is not connected and there is no minimum load resistor on the output jack or diode from plate to ground, as is found in some amps.

I don’t know who first thought this up, but I mentally thank them each time I have to test a transformer. Go ahead – try it!

R.G. Keen
Chief Engineer
Visual Sound
www.visualsound.net


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## Frenchy99 (Oct 15, 2016)

greco said:


> I found this to educate myself and thought others might enjoy reading it, especially the OP.


Thanks !!! 

Very similar test but very useful ...Will make up a NE-2 tube with 100K resistor to have hand... will try it out also !!!

I need to place my order for caps today... $300 worth of caps in this baby !


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## Budda (May 29, 2007)

Oof!


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## Frenchy99 (Oct 15, 2016)

OK, I changed all the bleeders, resistors, rectifier cap ( not all shown on the pictures here) the only thing not done are the 5 large can Caps...

Every time I sum up the courage to order the can caps, I find another amp to buy !!! 

This is getting to be an expensive hobby... 

I am tempted to plug this thing in to see if its working even with the old can caps !!! 

What do you guys think ???


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## Granny Gremlin (Jun 3, 2016)

My tech refuses to replace caps unless there is a demonstrated problem. Does you mm measure capacitance? Check em and leave them if good. There can be other issues ( measure fine but draw too much current) but if the voltage dropping resistor after the can is not burnt that's probably not the case.


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## cboutilier (Jan 12, 2016)

Frenchy99 said:


> OK, I changed all the bleeders, resistors, rectifier cap ( not all shown on the pictures here) the only thing not done are the 5 large can Caps...
> 
> Every time I sum up the courage to order the can caps, I find another amp to buy !!!
> 
> ...


Do you have room on the outside of the chassis to retrofit Fender style axial filter caps?


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## Frenchy99 (Oct 15, 2016)

Granny Gremlin said:


> My tech refuses to replace caps unless there is a demonstrated problem. Does you mm measure capacitance? Check em and leave them if good. There can be other issues ( measure fine but draw too much current) but if the voltage dropping resistor after the can is not burnt that's probably not the case.



With the hassle of disconnecting them to test them, might as well replace them... More worried that they might go once power is applied since been dried out and out of use for 25 years...

I'm off today and will take the time to place an order.


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## Frenchy99 (Oct 15, 2016)

cboutilier said:


> Do you have room on the outside of the chassis to retrofit Fender style axial filter caps?


No room whatsoever... 

Plus I m a bit of a purist... I would like to keep the look as close as possible. 

I might decide to go with the JJ can caps and install the clamps for them. The Mallory twist can replacement at $50 US a can is quite expensive.... this is the reason why my order was not placed in the first place... 300$ for 5 caps !!!


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## jb welder (Sep 14, 2010)

Frenchy99 said:


> No room whatsoever...
> 
> Plus I m a bit of a purist... I would like to keep the look as close as possible.


Modern caps are much smaller. It's not hard to hollow out the original cans and stuff them with modern axial or radial types. New caps that look original.


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## Lincoln (Jun 2, 2008)

I'm at that same place with my pro 200. Original filter cap cans are 80/80 @ 350V, run in series to make 40 uF @ 700 volts. I can't find any 80/80 cans. I was wondering if using 100/100 cans and ending up with 50 uF would be ok? I bought some 80 uF axial caps a while back. They are huge. Don't think they'll fit in the old cans.


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## Frenchy99 (Oct 15, 2016)

Lincoln said:


> I'm at that same place with my pro 200. Original filter cap cans are 80/80 @ 350V, run in series to make 40 uF @ 700 volts. I can't find any 80/80 cans.



Yep... The larger Garnet s are the most expensive amps to recap!

The 200 is just as expensive to recap as the 400 or the 600... 

That means , if you go with the direct CE replacement. Your looking at $300 for 5 caps... 

or...

You can use 4 of these to replace the 80-350 
JJ Can Capacitor 50µF x 50µF / 500V | TubeDepot.com
and buy the clamps to install them.

and the final multi cap, buy the CE replacement... this one you have to bite the bullet...
CE - USA 40Fx40Fx20Fx20µF / 525V | TubeDepot.com


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## Granny Gremlin (Jun 3, 2016)

OK, but you can do better than Tubedepot's prices most of the time. IIRC the caps were actually the worst for that.


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## Lincoln (Jun 2, 2008)

Frenchy99 said:


> Yep... The larger Garnet s are the most expensive amps to recap!
> 
> The 200 is just as expensive to recap as the 400 or the 600...
> 
> ...


Garnets use a lot more/larger filter caps then Fenders do, that for sure.

I went with 2 of 100/100 uF @ 500V cans. tie those together to make a couple 50 uF @ 1000V for the first 2 stages of filtering. JJ's were about $11 each, F&T's were $19, I went with the F&T's.
And I got the CE 40/40/20/20 for $38

I bought Sprague 80 uF axial caps years ago for it, had a board made up for them, but I really didn't want to venture that far from original so I kept putting off the swap till it never happened. 
I'll only need to use 3 cans to replace the 4, the forth old can I'll leave in place not hooked up. Seems to be the best way to go, for me anyway.


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## Granny Gremlin (Jun 3, 2016)

Couldn't you have saved some cost by using lower rated caps - surely the Garnet doesn't need 1000volters?


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## Lincoln (Jun 2, 2008)

Last time I checked, it was over 600 volts at the first filter cap. I've got 50/50's kicking around but they are only good for 500 volts. I haven't seen any 80/80 or 100/100 cans in 300v or 350 volt or I'd go with them.
Original is 80/80 @ 350V. The 100uf cans were the only option I could find other than going to a board and axials.


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## Granny Gremlin (Jun 3, 2016)

Yeah, fair enuf.


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## jb welder (Sep 14, 2010)

Lincoln said:


> I bought some 80 uF axial caps a while back. They are huge. Don't think they'll fit in the old cans.


I hope they weren't the blue Sprague type. Those are a small modern cap inside a much larger retro looking shell.


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## Frenchy99 (Oct 15, 2016)

I was going to order from tube Depot since they carry the CE multi caps plus for the volume discount on 10 tubes.. need to order 10 X matched El 34 .... my oder tands at about 500$ us at the moment... not closed yet... just went to my local places this morning to see what I could pick up here first... if you have a cheaper place that carry the CE and have good prices on matched tubes! I' m all ears ...


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## Frenchy99 (Oct 15, 2016)

Garnets are just expensive to recap. ...


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## jb welder (Sep 14, 2010)

As far as values and voltages, don't worry too much about going larger on the value, like from 80 to 100uF. Cap tolerances used to be -20/+80% . The only place where you don't want to go much bigger is right after a tube rectifier.
For voltage, use something that gives a bit of leeway for the voltage that is actually present. For the totem pole arrangements, they used whatever was most commonly available that met their needs. So if they needed 550V and the next common up from 500V meant two 400V's in series, that's what they would use. If they could have got two 300V's, they would have used that. If you need 650V and you can get 350V's, use two in series instead of higher voltage ones that may have been more common when the amp was built.


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## Frenchy99 (Oct 15, 2016)

There is two 8o Uf 350V in series in these already... they are the problem to replace.

Either use 4 X 50Uf50V or use the CE 4x20Uf 525V ...

I didn' find any other solution.


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## Lincoln (Jun 2, 2008)

jb welder said:


> I hope they weren't the blue Sprague type. Those are a small modern cap inside a much larger retro looking shell.


Ah.......they are blue for sure. I'll get a picture up when I get home tonight. They are very large caps.


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## Lincoln (Jun 2, 2008)

Frenchy99 said:


> I was going to order from tube Depot since they carry the CE multi caps plus for the volume discount on 10 tubes.. need to order 10 X matched El 34 .... my oder tands at about 500$ us at the moment... not closed yet... just went to my local places this morning to see what I could pick up here first... if you have a cheaper place that carry the CE and have good prices on matched tubes! I' m all ears ...


This is where I get them from. They ship instantly, I use the DHL option and the order arrives in 2 days every time. Arizona to Alberta. Border fee is approx. $20

Capacitors - Multi-Section / Can Type | Antique Electronic Supply


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## jb welder (Sep 14, 2010)

Lincoln said:


> Ah.......they are blue for sure. I'll get a picture up when I get home tonight. They are very large caps.


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## Lincoln (Jun 2, 2008)

jb welder said:


>


Yeah.......that's exactly what they look like only 80uF and much larger. I thought Sprague Atom was the best sh1t you can buy?


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## Lincoln (Jun 2, 2008)

Here's the picture of the board I made up to take the place of the cap cans in my Pro 200. The caps are so big you can barely see the board. it was so fugly, I never used it or even soldered it up.








What you're looking at is 4 x 80uf, a 50uf, a 40uf, and just look at that tiny little 20uf/450V at the end.


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## Frenchy99 (Oct 15, 2016)

Lincoln said:


> What you're looking at is 4 x 80uf, a 50uf, a 40uf, and just look at that tiny little 20uf/450V at the end.



Wow... your doing the Fender type variation ! 

Is there room on the 200 for your board ? have you tried different position ?

That would be a great solution if room...


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## Lincoln (Jun 2, 2008)

Frenchy99 said:


> Wow... your doing the Fender type variation !
> 
> Is there room on the 200 for your board ? have you tried different position ?
> 
> That would be a great solution if room...


There is room for this on the 200, and I was going to go Fender, but I changed my mind and I'm going with cans. I thought I was buying the best caps money could buy, but they're actually "fake" sized and made for more show than go. 
@jb welder brought it to my attention.


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## jb welder (Sep 14, 2010)

Lincoln said:


> View attachment 179761
> 
> just look at that tiny little 20uf/450V at the end.


That gives you an idea of what you can get as far as re-stuffing old cans. And you can series or parallel them inside the old cans too.


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## Lincoln (Jun 2, 2008)

jb welder said:


> That gives you an idea of what you can get as far as re-stuffing old cans. And you can series or parallel them inside the old cans too.


yup, I see the light brother.  

So, give it to me straight......is F&T worth the extra money over JJ? And we're still avoiding Illinois Capacitor, right?


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## jb welder (Sep 14, 2010)

I'm still avoiding the Illinois.  They may well have fixed whatever their problem was, but who wants to take the chance to find out?
As far as JJ or F&T, I don't know if the difference in quality would be equal to the difference in price. Probably not for me, but some may not care about the added expense.
F&T has been around a long time and has a good reputation. And we all know what Vince the shamwow guy said about Germans "they make good stuff".


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## Frenchy99 (Oct 15, 2016)

Got tired of not knowing were I stand so far on the 600 so... with all the parts changed so far without the can caps.. I plugged it in my varia and I have it at 25 volts so far for the last 5 min without any glitches. .


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## Frenchy99 (Oct 15, 2016)

IT' S ALIVE!!! IT' S ALIVE !!! 


HNG^%$HNG^%$HNG^%$


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## Frenchy99 (Oct 15, 2016)

Its been running for the last 3 hrs with only 2 power tubes. 

I jammed on it for an hr or so... 

This baby is good to go...

Which means I will invest in the caps and new tubes without any worries... 

Its fun when a plan comes together !!! 

I had a dream... a dream of playing a monster Garnet !!! 

HNG^%$


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## greco (Jul 15, 2007)

Well Done!! Congrats!

Enjoy the monster!


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## Frenchy99 (Oct 15, 2016)

Lincoln said:


> So, give it to me straight......is F&T worth the extra money over JJ? And we're still avoiding Illinois Capacitor, right?


F & T's are rated for more hours than JJ's, good choice.


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## Frenchy99 (Oct 15, 2016)

Anyone know where I can source these black switches ??? Antique electronic don't seem to carry them ...


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## Frenchy99 (Oct 15, 2016)

For the Tech guy`s...

I'm trying to finish my order and decided to order the can caps for the 200 at the same time.

My problem here is that the CE Mfg., 525V, 40/40/20/20uF are out of stock at the moment.

Would using the CE Mfg., 525V, 40/40/40uF instead be fine on the 200 ??? For the multi section cap that is...

The multi cap calls for 40/40/20 ... the 20 is feeding the stinger... Would 40 affect the sound or be to much ???


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## Granny Gremlin (Jun 3, 2016)

Use proper metal ones - those plastic ones break too easy - Gar never should have ... wait for it... switched.


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## Granny Gremlin (Jun 3, 2016)

Granny Gremlin said:


> OK, but you can do better than Tubedepot's prices most of the time. IIRC the caps were actually the worst for that.


I take this back - I am always conflating Tubedepot.com with TheTubeStore. com.


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## Frenchy99 (Oct 15, 2016)

Granny Gremlin said:


> I take this back - I am always conflating Tubedepot.com with TheTubeStore. com.


No worries... Its expensive no matter where you buy...

I just bought from Fliptop , want to try those new 600Volts caps in the Garnets. The order has not arrived yet.

I also placed an order at the Antique Electronic Supply... Ouff... $60 in shipping, got the order the next day, missing some items that were back order but was not advised that they were... plus got hit with $92.00 of duty fees... 

I decided to do major recap jobs... its expensive...


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## Frenchy99 (Oct 15, 2016)

This baby will benefit of 6 brand new matched power tubes !!! 

Cant wait to be finished and crank her up !!! HNG^%$


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