# Garnet rebuild project.



## Frenchy99 (Oct 15, 2016)

I just picked up a major project ! 😓 

Got me a Deputy bass amp G100B (pair of 6L6 tubes) that was partially converted to a solid state amp ! 🤯😱🤯 The cabinet is in great condition but I need a new OT and PT to even consider breathing life in this abused amp ! 🙄

Here are pics of it as I got it.


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## Frenchy99 (Oct 15, 2016)

Like I said, the cabinet is in great condition and it has a decent 15 inch speaker in it.











So pulled the speaker and put it away in the speaker closet and the cab went into storage.

Now for the fucked up head ... 










The inside is worst...











What the F... happened in here ??? 😱


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## Frenchy99 (Oct 15, 2016)

I dont even know what was the plan here...



















Let start by saying that I went to buy another amp, which I did, but the seller offered me this for little so...

Being a sucker for Garnet stuff, brought it home.



















Chassis looks in good shape apart from all the weird stuff added.


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## Frenchy99 (Oct 15, 2016)

So decided to do a small clean up and remove all the foreign items inside.










I still have lots to work with.










Just need to re-solder the rectifier circuit properly.










Missing a pot and need to follow the circuit and verify all connections.










Yep... lots of work...


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## Frenchy99 (Oct 15, 2016)

One good news. The seller gave me an old output transformer he had.










Its an old 1965 Hammond 2065 Output Transformer : 
60 Watts, 3800 ct Impedance, 200 sec Ma. 

Wondering if its to big for this amp and what to use as a PT to go with it ? ... 

Looks good !










The chassis looks nice also after the clean up.


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## player99 (Sep 5, 2019)

You should get a Garnet tattoo.


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## Frenchy99 (Oct 15, 2016)

player99 said:


> You should get a Garnet tattoo.


Got a t-shirt !


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## Lincoln (Jun 2, 2008)

Frenchy99 said:


> Got a t-shirt !


I need a Garnet T-shirt. I'll get the wife working on that. 

Why would anyone do that to a Garnet amp?

Very little filtering for a garnet. Are you missing some filter cans?


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## player99 (Sep 5, 2019)




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## player99 (Sep 5, 2019)




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## Frenchy99 (Oct 15, 2016)

Lincoln said:


> I need a Garnet T-shirt. I'll get the wife working on that.


Great stocking stuffing ! 



Lincoln said:


> Why would anyone do that to a Garnet amp?


Mental health issues ? 



Lincoln said:


> Very little filtering for a garnet. Are you missing some filter caps?


3 versions of the Deputy exist.

Deputy , 40 watts ( 2 6L6) like the one on here, just one filter can.
Deputy I , 50 watts (2 EL34) 5 filter cans
Deputy II , 100 watts (4 EL34) 5 filter cans

Two 6L6 need less filtering I guess...


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## Frenchy99 (Oct 15, 2016)

Just read that the transformer that I have is a Modulation transformer. Can these be used as an ouptput transformer in an amp ???

Hammond 2065 Modulation Transformer :
60 Watts, 3800 ct Impedance, 200 sec Ma.


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## Latole (Aug 11, 2020)

Output Transformer is never too big. 
Often, bigger mean better tone.

A bigger OT don't need more power from a PT, it is a passive components.

Same if you use a 10 watts resistor to replace a 1/2 watts resistor.


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## Latole (Aug 11, 2020)

Frenchy99 said:


> Just read that the transformer that I have is a Modulation transformer. Can these be used as an ouptput transformer in an amp ???
> 
> Hammond 2065 Modulation Transformer :
> 60 Watts, 3800 ct Impedance, 200 sec Ma.


No good for a guitar tubes amps use :
First, frequency response are only from 150 to 7,000 hz 
Guitar amp transformer go to 15Khz

From wikipedia;

A *modulation transformer* is an audio-frequency transformer that forms a major part of most AM transmitters. The primary winding of a modulation transformer is fed by an audio amplifier that has about 1/2 of the rated input power of the transmitter's final amplifier stage. The secondary winding is in series with the power supply of that final radio-frequency amplifier stage, thereby allowing the audio signal to lower and raise the instantaneous DC supply voltage of the power amplifier (PA) tube or transistor. Considering that the PA device is operated as a class-C amplifier, i.e. as a switch, the modulation transformer is responsible for the amplitude modulation (AM) of the transmitter.


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## Latole (Aug 11, 2020)

Modulation transformer AM radio transmetters circuit .

Transformer is before the output stage


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## Always12AM (Sep 2, 2018)

I’d highly suggest looking at some fresh Hammond trannies. I ordered a pair in May and they were excellent. Ordered another pair, and they turned out to not be needed and they honoured the return after 35 days and were quite good to do business with.

But if you are ordering from one of their suppliers, just know that they might be shipping from Texas even though they are made somewhere near Cambridge. Not a big deal, just might take longer unless you are like me and are willing to pay more for UPS.


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## Latole (Aug 11, 2020)

Hammond are very good,
You can order from them Ottawa 





Amp Transformers & Chokes - Canada


Transformers and chokes for building or repairing guitar, bass, and other amplifiers.




nextgenguitars.ca


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## Paul Running (Apr 12, 2020)

Frenchy99 said:


> Just read that the transformer that I have is a Modulation transformer. Can these be used as an ouptput transformer in an amp ???
> 
> Hammond 2065 Modulation Transformer :
> 60 Watts, 3800 ct Impedance, 200 sec Ma.


Experiment and try it out for yourself, only you know the sonic qualities that you desire.


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## dtsaudio (Apr 15, 2009)

Won't work. It can't drive a speaker. Output is 3000 ohms.


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## Paul Running (Apr 12, 2020)

Use the Modulation TFM to drive the grids of the output tubes...how much output power are you looking for...500-600W?


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## Paul Running (Apr 12, 2020)

Instead of screen-modulation.


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## Latole (Aug 11, 2020)

Are we sure this modulation transformer is working ?
No, IMO


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## ezcomes (Jul 28, 2008)

Frenchy99 said:


> The inside is worst...
> 
> 
> View attachment 342270
> ...


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## Granny Gremlin (Jun 3, 2016)

What a massacre in there.


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## tomee2 (Feb 27, 2017)

What was the transistor on the heatsink? Some later mod or part of the original amp?


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## Frenchy99 (Oct 15, 2016)

Granny Gremlin said:


> What a massacre in there.


We can re-build him !


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## Frenchy99 (Oct 15, 2016)

tomee2 said:


> What was the transistor on the heatsink? Some later mod or part of the original amp?


All new added junk...

It makes no sense to me. Its a good thing it was almost given to me since lots of time and money needs to be put into it. Mind you, newer transformers would be a major upgrade on this model.


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## tomee2 (Feb 27, 2017)

Wow. Ok, so new transformers and rewiring - that's a lot of effort!


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## jb welder (Sep 14, 2010)

You're a brave man Frenchy. Most of us would have walked away from this one I think.
Hopefully it won't run you 6 million, Oscar.


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## Frenchy99 (Oct 15, 2016)

jb welder said:


> You're a brave man Frenchy. Most of us would have walked away from this one I think.
> Hopefully it won't run you 6 million, Oscar.



Lol...

Trust me, I almost walked away from it myself. 

I contacted Larry Kohut from Red Rock Amps since he is a specialist on these Garnet`s, he advised me as to what would be the best replacement transformers for this model. Both new Hammond transformers are beefier compared to the old ones and are improvements. Larry`s work is impressive. 

I was real lucky that he he took the time to help me out ! Big thanks goes out to him.

So, made the decisions to go forward on this project. Will do my best to breath life in this old girl... 











She will run again...


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## Lincoln (Jun 2, 2008)

I was going through some old stuff on an old memory stick yesterday, and I found a two part schematic for the beast. With a single filter can!


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## Lincoln (Jun 2, 2008)




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## Frenchy99 (Oct 15, 2016)

Lincoln said:


> View attachment 342556
> View attachment 342558


Thank you for these. Only had the guitar version .


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## Paul Running (Apr 12, 2020)

May I ask the Hammond P/N that you went with for your power and output transformers?


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## Frenchy99 (Oct 15, 2016)

Paul Running said:


> May I ask the Hammond P/N that you went with for your power and output transformers?


For this build of the Deputy:

Power Transformer – Hammond 290CX

Output Transformer – Hammond 1760J

They also match the bolt pattern of the chassis.


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## Paul Running (Apr 12, 2020)

Are you re-building to Garnet Deputy 6L6GC original version?


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## Frenchy99 (Oct 15, 2016)

Paul Running said:


> Are you re-building to Garnet Deputy 6L6GC original version?


Yes

Just with a little beefier PT and OT for better performance, the original transformers were a little on the weak side for a pair of 6L6 tubes. I`m not looking at changing the voicing of the amp since the rest of the amp is almost all complete, just some parts of the input board needs rebuilding. I want the Garnet sound.


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## Paul Running (Apr 12, 2020)

Sounds good. Can you authenticate this schematic of the preamp as the original circuitry? and were they OEM-fitted with 6L6GCs?


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## Frenchy99 (Oct 15, 2016)

Paul Running said:


> were they OEM-fitted with 6L6GCs?


Yes , this model was. Several different variation of the Deputy exist. I also have a Deputy 2 that comes with four EL34 power tubes.



Paul Running said:


> Can you authenticate this schematic of the preamp as the original circuitry?


Yes, this is the Pre for the Deputy but mine is a little different since it is the bass version. The reason why I am having a harder time verifying all the circuit since no Schematic is available for the Deputy Bass version of the amp. Just like no schematic exist for the Deputy 2 amp...


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## Frenchy99 (Oct 15, 2016)

Yay !

My transformers came in.

Will be able to start on this baby .










Great sevice from NextGen.


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## Paul Running (Apr 12, 2020)

Does this mean no sleep for the next couple days?


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## Frenchy99 (Oct 15, 2016)

Paul Running said:


> Does this mean no sleep for the next couple days?


I never sleep !


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## Lincoln (Jun 2, 2008)

Frenchy99 said:


> I never sleep !


no time for sleep when you're busy running from town to town, scooping up incredible deals!


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## Frenchy99 (Oct 15, 2016)

OK, well decided to start on this baby...

I added both transformers on the chassis.










Lots of wires !










But looks good on the other side ! 










These were direct drop ins...


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## Paul Running (Apr 12, 2020)

Looking nice and clean.


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## Frenchy99 (Oct 15, 2016)

Spent a little bit of time yesterday night soldering the transformer wires.










Changed some of the existing wires, will be needing more parts that I forgot to order and some that I wasn't expecting... The OT has 4-8-16 tabs and would like to install a 3 way selector switch but no one in Canada carries them... so next order will have to be from Antique Electronics.

Will have to change 2 of the diodes since they were cut off, I reattached them for now but doesn't look pretty...











I installed a new Strip board to replace the missing one but the resistors leads are not long enough any more since were snipped off before... was going to change all of them but the new resistor leads are even shorter !!! 

Its not going to be pretty here also... 

Will continue tonight...


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## Paul Running (Apr 12, 2020)

Frenchy99 said:


> I installed a new Strip board to replace the missing one but the resistors leads are not long enough any more since were snipped off before... was going to change all of them but the new resistor leads are even shorter !!!


If you have the time, you could extend the short leads, with 20 gauge, solid hook-up wire. Just strip the wire, apply flux and tin the copper, then attach with your favourite joint and viola...it doesn't look stock but do you care?


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## Frenchy99 (Oct 15, 2016)

Finally got more parts so made some more work on the head.

Finished the input board.









Went thru the diagram to find all the missing parts. Hope I didn't miss anything.









Its starting to look like an amp.










The 2 cut diodes bothered me, so replaced them. Did a full cap job on the amp while I was at it.


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## Frenchy99 (Oct 15, 2016)

Since I didn't know why both transformers were gone on the amp, took good measure to change the multi cap also.

Went with a little higher rating and voltage since this amp was made for bass. 

Here is the difference between the two.









The old cap had the first two parts tied together for 40uf. I`m giving this baby 80.










I'm not done since don't have a 3 way selector switch for the impedance ... No one local carries them.


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## Frenchy99 (Oct 15, 2016)

I`ll go over it again to make certain I didn't miss anything and might just plug a speaker on it to test it.

Looks good.


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## Paul Running (Apr 12, 2020)

Looking good! I notice that there is a 5VAC, 3A secondary on your PTFM. Are you a fan of the tube rectifier?


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## nonreverb (Sep 19, 2006)

Paul Running said:


> Looking good! I notice that there is a 5VAC, 3A secondary on your PTFM. Are you a fan of the tube rectifier?


I'd be wary of using a tube rectifier with an 80uF cap.


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## nonreverb (Sep 19, 2006)

Frenchy99 said:


> I`ll go over it again to make certain I didn't miss anything and might just plug a speaker on it to test it.
> 
> Looks good.
> 
> ...


Excellent work Pierre!


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## Frenchy99 (Oct 15, 2016)

Paul Running said:


> Looking good! I notice that there is a 5VAC, 3A secondary on your PTFM. Are you a fan of the tube rectifier?


Not going tube rectified on this one, don't want to start modifying the chassis and all.


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## Frenchy99 (Oct 15, 2016)

nonreverb said:


> I'd be wary of using a tube rectifier with an 80uF cap.


Would the the higher filtering be all that bad for a tube rectified ? Trying to learn...



nonreverb said:


> Excellent work Pierre!


Thank you ! Doing my best. My soldering skills need lots of work.


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## nonreverb (Sep 19, 2006)

Frenchy99 said:


> Would the the higher filtering be all that bad for a tube rectified ? Trying to learn...
> 
> 
> 
> Thank you ! Doing my best. My soldering skills need lots of work.


The problem with higher capacitance is the time it takes to fully charge it. The moment the power is switched on, the tube sees almost a dead short across the cap as it has no charge. The bigger the capacitance, the longer the rectifier has to work near max. to fill the cap. Over time this can stress the tube to a point where it fails. 80uF doesn't sound like a big cap but for a 5AR4 for instance, the recommended limit is around 50 or 60uF. It doesn't mean it will be destined to fail, but you'd be stressing it undoubtedly.
Diodes have advantages as they transfer power instantaneously, have almost zero drop across them and have significantly higher current ratings than tubes....Hence why solid state stereo equipment can have filter caps in the 1000's of uF's.


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## Frenchy99 (Oct 15, 2016)

nonreverb said:


> The problem with higher capacitance is the time it takes to fully charge it. The moment the power is switched on, the tube sees almost a dead short across the cap as it has no charge. The bigger the capacitance, the longer the rectifier has to work near max. to fill the cap. Over time this can stress the tube to a point where it fails. 80uF doesn't sound like a big cap but for a 5AR4 for instance, the recommended limit is around 50 or 60uF. It doesn't mean it will be destined to fail, but you'd be stressing it undoubtedly.
> Diodes have advantages as they transfer power instantaneously, have almost zero drop across them and have significantly higher current ratings than tubes....Hence why solid state stereo equipment can have filter caps in the 1000's of uF's.


Thank you for the information. Always leaning.


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## bzrkrage (Mar 20, 2011)

B&E Calgary


Frenchy99 said:


> I'm not done since don't have a 3 way selector switch for the impedance ... No one local carries them


Need me to get one for you? It’s not a problem.


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## Paul Running (Apr 12, 2020)

Frenchy99 said:


> Would the the higher filtering be all that bad for a tube rectified ? Trying to learn...


Here's a blurb that you may find helpful:


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## Frenchy99 (Oct 15, 2016)

bzrkrage said:


> B&E Calgary
> 
> Need me to get one for you? It’s not a problem.


Thanks for the offer but its a .3 amp... Wonder if sturdy enough for the application. 

This is the one I was thinking at ordering. Would order 4 or 5 to make it worth it.

Switch - Rotary, 1 Pole, 3 Position | Antique Electronic Supply (tubesandmore.com)


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## Frenchy99 (Oct 15, 2016)

I currently have some heavy duty on-on switch on hand so might just drop the 16Ohm for now and just install the 4 and 8 that I currently use with my cabs.


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## Paul Running (Apr 12, 2020)

Frenchy99 said:


> Thanks for the offer but its a .3 amp... Wonder if sturdy enough for the application.
> 
> This is the one I was thinking at ordering. Would order 4 or 5 to make it worth it.


You should be good with that voltage and current rating.


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## nonreverb (Sep 19, 2006)

Paul Running said:


> Here's a blurb that you may find helpful:


Good article. As stated though, to spec the proper voltage for the amp with a 1st-stage choke would require a rethink of the power transformer as the choke voltage drop would definitely affect plate voltage values and ultimately, performance.


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## Frenchy99 (Oct 15, 2016)

I stopped at a local place yesterday and was happy to find what I needed for the output selector.

Here is the switch.









So I installed it this afternoon.










I was so excited finding the switch that forgot the last cap I needed to finalize the amp. The amp has a separate 22Uf/450V cap install further down on the amp. it usually is part of the multi can and I do have it free on the new multi cap but would need to change all the wires and resistors... Will just wait till next trip to the store.
Wanted to see if my work paid off...

Double verified everything...


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## Frenchy99 (Oct 15, 2016)

So, pulled some nice vintage pre amp tubes tested and proven and a nice balanced set of power tubes.

Installed everything, plugged everything in my variac, on stand by , upped the juice !!!

No burning smell or smoke !!! 

I also plugged the power tubes in my bias probe, took the amp off stand by and voila !










Nicely matched tubes !

Opened the guitar volume and Wow !!! 

This thing rocks !!! 

This baby is back from the dead !!! 

Pulled some new knobs to give it the Garnet look.




























This amp is now brand new all around and sounds better, has more power reserve then the original. Just needs one more cap replacement and it goes back in its cab.

Amp almost done !!!

Its alive !!!


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## bolero (Oct 11, 2006)

hey really interesting thread!

I have a Deputy head: I'd like to get it to sound more like my old jtm45 instead of the bright late 60's marshall circuit it appears to be inspired by

clipped the bright cap on CH1 but didn't make any difference, really

Frenchy are you building yours up to match the Garnet schem?


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## bolero (Oct 11, 2006)

oh, you're done!! ha. took a while for the pictures to load

fwiw mine has 2x EL34 so I guess it's a Deputy I model. seems to match the schem in the Garnet book ( and posted here on P2 I think )


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## Frenchy99 (Oct 15, 2016)

bolero said:


> Frenchy are you building yours up to match the Garnet schem?


Hey Bolero, 

Yes I built it up to the Garnet Bass specs. No schematics for the bass version exist for the Deputy so I used pictures of the exact same bass amp and similar bass schematic for the G100B version to confirm the values of the parts.



bolero said:


> clipped the bright cap on CH1 but didn't make any difference, really


It should make a small difference. Id have to look up the schematic for you amp but based on looking at a few pictures that I have, values of the components are nowhere near mine. Mine is more Bass friendly.



bolero said:


> fwiw mine has 2x EL34 so I guess it's a Deputy I model.


Yep, yours would be a Deputy I , more powerful. should be 55-60 Watts compare to my 45 watts.

Completely different model compared to mine to tell the truth. different voicing also.




bolero said:


> seems to match the schem in the Garnet book ( and posted here on P2 I think )


It should not match the G100 model at all poste on page 2 here! Yours is not that model. Big difference between the 2 in the power and filtering.


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## bolero (Oct 11, 2006)

Paul Running said:


> Sounds good. Can you authenticate this schematic of the preamp as the original circuitry? and were they OEM-fitted with 6L6GCs?
> 
> View attachment 342753
> View attachment 342753


Frenchy it is this one posted by Paul on p2. I snipped the 230 Pf cap to no avail, still way too bright

But will compare it to your bass schem posted earlier, maybe I can tame it. Strangely, the normal channel sounds very dull: you'd think it would be ok to use with gtr. maybe that is close to your bass circuit


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## Paul Running (Apr 12, 2020)

It's too bright because the plate coupling-cap is a low value, 2000pfd or .002ufd. To roll-off the high-end sooner...increase the value of the cap...for myself I would give10,000pfd or 0.01ufd a first-shot effort:


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## Paul Running (Apr 12, 2020)

The Normal channel is dull because the cathode by-pass cap value is high...you might want to reduce that value to 0.68 - 2.2ufd. That V1a is biased hot...recheck the value of the 820 ohm cathode-resistor...if it has drifted low...I would replace it...12AX7s begin to cry at 820 ohms...with that plate loading for a 12AX7, the standard is 1K5 ohms.
If you are picking up unwanted EMI, I'd put in control-grid stoppers...39K to 82K ohms...depending on the quality of your tube.


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## tomee2 (Feb 27, 2017)

Paul Running said:


> The Normal channel is dull because the cathode by-pass cap value is high...you might want to reduce that value to 0.68 - 2.2ufd. That V1a is biased hot...recheck the value of the 820 ohm cathode-resistor...if it has drifted low...I would replace it...12AX7s begin to cry at 820 ohms...with that plate loading for a 12AX7, the standard is 1K5 ohms.
> If you are picking up unwanted EMI, I'd put in control-grid stoppers...39K to 82K ohms...depending on the quality of your tube.
> View attachment 348128


Why would an 820 ohm resistor and 250uF cap be used there? Was there a reason to use those values originally if they don't work so well?
Lower distortion? Or tube life?
Just curious, not questioning your recommendations.
In old hifi amps, eico Heathkits etc. I see 25uF or 50 uF bypass caps. Macintosh mc60 has 100uF on the 1st 12ax7, about the biggest I can find in my old tube hifi schematics.


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## bolero (Oct 11, 2006)

Thanks Paul! very useful stuff

the 820 ohm + 250uF cap seems to be pretty common, on the early Marshall schems in the Doyle book


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## Paul Running (Apr 12, 2020)

tomee2 said:


> Why would an 820 ohm resistor and 250uF cap be used there? Was there a reason to use those values originally if they don't work so well?
> Lower distortion? Or tube life?


Those values will actually enhance distortion. The 250ufd cap will virtually eliminate cathode feedback...degenerative feedback reduces distortion. Depending on the plate voltage to the 12AX7, the 820 ohm cathode resistor may offset the center-bias point which will produce distortion at lower input levels. Below is an RC amp chart for a GE 12AX7...if the plate voltage is 300VDC, then the 820 ohms is fine with a 100K ohm plate load. Most amps operate the first stage at the 180VDC plate column (Ebb=180 Volts).
Imagine the tube as a constant...the components connecting the inputs and outputs are variables. You should have at least one constant to accurately predict an outcome of anything in life...the more constants the greater the accuracy for a prediction. When a tube is replaced with a new constant the outcome will be different.


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## Jerome (Dec 4, 2015)

Nice work on restoring that Garnet . I would think those Hammond transformers would be an upgrade on the originals . Wondered if that impedance selector switch is robust enough ? There is fairly high current flow through that switch , maybe 4 amps sometimes .


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## Jerome (Dec 4, 2015)

Three Position Rotary Switch


Don't let a weak switch deteriorate your sound. This heavy duty (6A @ 120V) phenolic resin switch with break-before-make phosphor bronze and silver plated contacts is the perfect path for the sound of your amp on its way to the speakers. Mounts in a 7/16" chassis hole.




tubedepot.com


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## Frenchy99 (Oct 15, 2016)

Jerome said:


> Three Position Rotary Switch
> 
> 
> Don't let a weak switch deteriorate your sound. This heavy duty (6A @ 120V) phenolic resin switch with break-before-make phosphor bronze and silver plated contacts is the perfect path for the sound of your amp on its way to the speakers. Mounts in a 7/16" chassis hole.
> ...


The specs looked pretty good on the one that I installed.

TENSION 300VAC OU 200VDC

Capacité de courant 5 Ampères continus 

CONTACT Mesure 35A @ 110VAC ou VDC ou .15A @ 250VAC ou VDC


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## Frenchy99 (Oct 15, 2016)

Jerome said:


> Nice work on restoring that Garnet .


Thanks, finished yesterday on it. Finally removed the last cap and attached it to the multi cap since was not able to get a proper cap locally. 



Jerome said:


> I would think those Hammond transformers would be an upgrade on the originals .


Yep, the new Hammond are more robust. Amp sounds great, Played bass with it yesterday to final test it. Past 4 on the volume, this thing growls...



Jerome said:


> There is fairly high current flow through that switch , maybe 4 amps sometimes .


New switch is 5 amps.


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## Paul Running (Apr 12, 2020)

Frenchy99 said:


> Thanks, finished yesterday on it. Finally removed the last cap and attached it to the multi cap since was not able to get a proper cap locally.
> 
> 
> 
> ...


You could use the same method that is used on your Soundmaster. This is the output of mine. The octal plug is used as a shorting strip...to change impedance, place the jumper to 4, 8 or 16 ohms.


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## Jerome (Dec 4, 2015)

Hmmm... 35A @ 110VAC ou VDC ou .15A @ 250VAC ou VDC , shouldn't that read 350 ma at 110 VAC , not 35 A ? 
Or was that a typo ?


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## Frenchy99 (Oct 15, 2016)

Jerome said:


> Hmmm... 35A @ 110VAC ou VDC ou .15A @ 250VAC ou VDC , shouldn't that read 350 ma at 110 VAC , not 35 A ?
> Or was that a typo ?


I just copied and pasted from the web site. I saw 5 amps and bought it.

10WA367 Commutateur Rotatif Ajustable 1/4”, Court-circuitant tige en forme D, 4 Poles, Longueur de tige: 6.35x17.5MM (abra-electronics.com)


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## Frenchy99 (Oct 15, 2016)

Yesterday morning decided to remove the last cap and since did not find the right values local ( wasnt going to get an order shipped to me for one cap ) rewired it and attached it to the new multicap. This cap should have been part of the multi cap to begin with but for some reason, this model was built differently.

The last cap removed.









And rewired to be attached to the multi cap.









Amp is 100% finished and working better then expected ! 










Played bass on it yesterday and today. Its a wrap !

Now, need to take the cab out of storage, clean it , and put the combo back together !


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## Paul Running (Apr 12, 2020)

Good work.


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## nonreverb (Sep 19, 2006)

Frenchy99 said:


> Yesterday morning decided to remove the last cap and since did not find the right values local ( wasnt going to get an order shipped to me for one cap ) rewired it and attached it to the new multicap. This cap should have been part of the multi cap to begin with but for some reason, this model was built differently.
> 
> The last cap removed.
> View attachment 348350
> ...


Nice!!


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## jb welder (Sep 14, 2010)

Jerome said:


> Wondered if that impedance selector switch is robust enough ? There is fairly high current flow through that switch , maybe 4 amps sometimes .





Frenchy99 said:


> I just copied and pasted from the web site. I saw 5 amps and bought it.


The 10WA367 is a CK1457. As I understand, it can handle 5A continuous, but only 150mA while being switched. The 35A part must be an error.


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## ezcomes (Jul 28, 2008)

Very nice!!
Make sure to post a shot of them together!!


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## Frenchy99 (Oct 15, 2016)

ezcomes said:


> Very nice!!
> Make sure to post a shot of them together!!


Id want to but dont know were to put the cab afterwards. Its a big combo and can be left in the cold without the speaker and head chassis. If I put it back together, have to store it in the house... I have no more room under the bed for it !!! 

Need to shuffle some stuff to make room... Trust me, would love to put it back together at this point.

Just finished recapping a Bogen and a Grooms amplifier ...


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## Frenchy99 (Oct 15, 2016)

Shuffled some amps around and made room to bring this big guy inside the house. 

It`s amazing what one can fit under 1 queen size bed !  

Here are some pics of it being put back together.


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## Frenchy99 (Oct 15, 2016)

Need a chicken head knob for the impedance switch and need to dig up some casters since this big guy is quite heavy !

And the final outcome. 



















This was a fun project !


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## nonreverb (Sep 19, 2006)

Congrats! Looks fantastic Pierre!


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## Frenchy99 (Oct 15, 2016)

Thank you Richard,

Great learning experience. Made me study even harder to understand these amps. still so much to learn.

I might one day understand what you guys write on certain threads !


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## ezcomes (Jul 28, 2008)

That looks slick!
Congrats!


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## bolero (Oct 11, 2006)

I bet that is a great bass amp!!

congratulations on bringing it back to life!

I have a revolution combo that is a nice low power studio bass amp, too


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## Frenchy99 (Oct 15, 2016)

I think I have a bad speaker ! 

Maybe it was the speaker that killed the amp originally ???


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## Paul Running (Apr 12, 2020)

If the speaker presents a very high impedance for extended periods of time such as playing high-frequencies for an extended period at high volumes, that would stress the OPTFM and output tubes, of a tube amp... at least you know that your fuse protection system is operational. If you look at the response curve of a typical guitar speaker, you will note that from 100Hz to 5KHz, the impedance is 100 - 200 ohms. Most guitar amps are designed around a 4 - 16 ohm resistive load...odd when you consider that most of it's service is in the 100 - 200 ohm load region.








Here's s simple equivalent circuit of a speaker that may help you visualize what's happening as the frequency increases:









An here's a more complex model of a speaker:










and more complex:


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## tomee2 (Feb 27, 2017)

Frenchy99 said:


> I think I have a bad speaker !
> 
> Maybe it was the speaker that killed the amp originally ???


Do you have any spares? (What am I asking that for..of course you do!  )


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## Frenchy99 (Oct 15, 2016)

Did some test yesterday. I can plug the Deputy in any other cab and have no problem whatsoever but when I plug the combo speaker, it blows a fuse ?

I plugged a solid state amp to the combo speaker and the speaker has no problem. The speaker read 4.1 in resistance for a 4 Ohms speaker that I found a little weird. 

Will continue testing things after I finish with the snow removal. Buried down here...


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## Paul Running (Apr 12, 2020)

Frenchy99 said:


> The speaker read 4.1 in resistance for a 4 Ohms speaker that I found a little weird.


3.2 ohms DC, is typical for a 4 ohm speaker. Maybe operate with your SS amp with a 1KHz test signal and monitor the AC current at the suspect speaker...compare to a known good 4 ohm speaker.


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## Frenchy99 (Oct 15, 2016)

Paul Running said:


> 3.2 ohms DC, is typical for a 4 ohm speaker. Maybe operate with your SS amp with a 1KHz test signal and monitor the AC current at the suspect speaker...compare to a known good 4 ohm speaker.


I`m not that well equipped yet, no sound generator. Will pull the head out and triple verify everything and dig out another 15 inch speaker.

More later today...


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## Frenchy99 (Oct 15, 2016)

Found my problem. my Ohms switch no longer works !

»»All 3 selections are now open. guess that it burned out.

Guess will have to order those more rugged ones...

Will attach only the 4 ohms tap for now to see if will work with the combo speaker.


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## Frenchy99 (Oct 15, 2016)

Yep ! 

The switch was the problem.

Amp works no problem with the cab speaker now.

Details... always details...


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## Paul Running (Apr 12, 2020)

Hardwiring is still the most reliable and fail-safe method...it may not be convenient when wanting to change load-settings however, less worries...you don't want that gem going up in smoke...Murphy lurks everywhere.


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## Frenchy99 (Oct 15, 2016)

Paul Running said:


> Hardwiring is still the most reliable and fail-safe method...it may not be convenient when wanting to change load-settings however, less worries...you don't want that gem going up in smoke...Murphy lurks everywhere.


I understand hat you are saying but switch's do exist for this application. This one was rated for 5 amps which should have been sufficient. A dud or just misrepresentation ?


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## Paul Running (Apr 12, 2020)




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## Frenchy99 (Oct 15, 2016)

Lol...

Would need a much larger chassis !


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## Patrice Brousseau (Aug 12, 2020)

Resurrecting this thread:

I bought the same combo thursday and just finished the minimal recap today (electrolytics only). The original combo @Frenchy99 had the OPT wired only at 8 ohms so I guess the OEM speaker is 8. The 4 ohms tap (green) is simply soldered to an unconnected lug on a terminal strip inside.

I bought it specifically for bass playing and it rocks. Previous owner told me that it needed new tubes… but he was wrong: the two Sylvania’s 6L6GC read 85-90 on my Jackson tester.

I even tried it with an Eden 210XLT bass cab and it was quite loud! Love the dedicated « jumpered » input so I can blend the two channels.

In my case, I’ve mounted a terminal strip and replaced the original can (20-20-20-20 with the first two paralleled) with three discrete 47uf. The last one mounted far away was 22uf but I chose to replace it also with a 47uf.


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