# Garnet Gnome (from Granada stencil amp) reverb tank question



## SmoggyTwinkles (May 31, 2021)

Hey, 

First post but probably first of many. 

I picked up a Granada 15TR and it's a Garnet Gnome 1 x 6v6, 2x 12ax7 as far as I can tell. 

Super stoked, but the reverb tank is.......well it's a joke haha. 

I'm planning to upgrade the reverb tank and I was wondering how to figure out what Ohm or impedance I'd want both in and out and how to determine that. 

I have the schematic but not sure.....

I'd like to go with a 3 spring accutronics short tank long decay, but there are different options on the input and output. 

So just asking if anyone knows what I should do? 

Figure Long and McQuade can order me one even though they don't have them on their website. Trying to avoid paying shipping from the US if I can. 

Thanks in advance!


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## Latole (Aug 11, 2020)

" the reverb tank is.......well it's a joke haha."

What do you mean ? it is not working or ......?
It is not the reverb circuit issue ? Not the tank ?
Give specs of this tank if you can it may help to know impedance.

Read here : 









Granada D15TR


I recently paid $240 for this weird old amp from a guy I trade gear with semi regularly. It’s an old Granada, likely from the ‘70s, that’s been pretty well modified and has a rather interesting story in a binder to go with it. I thought I’d share the cool factor and see if anybody has any other...




www.guitarscanada.com





The original reverb was intermittent and had a very metallic tone when it did work, partially due to the very short reverb tank. It was replaced with an Accutronics 4AB3C1B, which almost looks a large in this little amp to me but it provides huge and crystal clear reverb, at setting 2 it sounds like you’re in the middle of a giant cathedral. It currently has a Fender Eminence 12” speake


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## Latole (Aug 11, 2020)

What a owner do ;


https://en.audiofanzine.com/tube-combo-guitar-amp/garnet/d15tr/user_reviews/r.100375.html




These are the changes I made to mine: 
-Installing a plug-strand 3 (with Ground) 
-Changing the capacitors out of date (Filter Caps) and complete inspection 
-Changing lamps for Mesa Boogie 
-Changing the speaker for a Celestion G12M Greenback 8ohm (note well the impedance if you change HP) 
-Changing the Reverb for USA 8AB2C1E Accutronics three spring (also note this number if you think the change! If you want to keep a two spring reverb used 1AB2C1E


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## Frenchy99 (Oct 15, 2016)

SmoggyTwinkles said:


> Super stoked, but the reverb tank is.......well it's a joke haha.


What type of problem do you have ? is it not working right ? 

I have a couple of 15TR and have no problem with the reverb tank.


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## Paul Running (Apr 12, 2020)

You might want to check the tubes for the drive and recovery of the reverb...a mix of 12AU7 and 12AX7:


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## Granny Gremlin (Jun 3, 2016)

Garnet typically used 8 ohm in and 3k Out tanks (see this Vintage Traynor and Garnet Amps Thread and read down).

Just watch out for the grounding ( easy to check because you can see on your amp what is grounded or not). Then it's a matter of putting together an Accutronics product code for all that (see their website). IF the grounding is wrong or the output Z not right then that could be it (there were a number of model numbers posted above - what's in there right now?). From the model number(s) in that other thread I linked above, none of the ones I see here are correct (but Gar changed shit up sometimes so check what's grounded at the tank in/out jacks and measure the DCR of the tank output to cross ref with the table on the Accutronics site). I'd also try subbing the driver and recovery tubes (and clean their sockets as well as the reverb send/return RCA jacks and plugs - I've had reverb not work just due to accumulated grime on those jacks).


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## SmoggyTwinkles (May 31, 2021)

Frenchy99 said:


> What type of problem do you have ? is it not working right ?
> 
> I have a couple of 15TR and have no problem with the reverb tank.


Ahhh, maybe it's decent but it's the tiniest reverb tank I've ever seen in an amp, especially in a cabinet this huge. 

L&M is going to try to order me a Accutronics 3 spring, short tank, long decay. 

I think I'm going to put this Gnome 7w TR into head format at some point. 

Also ordered a Jensen type speaker from Weber speakers today. 

First thing I gotta do though is get a 3 prong cord wired up, which I have but too busy to get around to it just yet. 

Thanks for the reverb info that was helpful choosing what I wanted.


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## Alan Small (Dec 30, 2019)

SmoggyTwinkles said:


> Hey,
> 
> First post but probably first of many.
> 
> ...


nextgen supplies tanks and is an active GC member.


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## SmoggyTwinkles (May 31, 2021)

Frenchy99 said:


> What type of problem do you have ? is it not working right ?
> 
> I have a couple of 15TR and have no problem with the reverb tank.


I haven't played it yet because it has a really janky looking power cord. Someone spliced the original and put one of those old screw in 3 prong plugs on the end and I want to be as safe as possible before I go ahead. 

The guy I got it off said everything works fine. He said he modded the Tremolo pot to be push pull (which it is) because he could still hear a bit of trem thump even with the Trem knob set to zero. So that's cool  pull up and it's on push down and it's out of the circuit. Nice mod!


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## SmoggyTwinkles (May 31, 2021)

Alan Small said:


> nextgen supplies tanks and is an active GC member.


Cool. I was just over at L&M and they showed me a catalog of stuff and found me the Benton Accutronics tank I wanted, $18.95 list price (probably in US dollars) so I'll let them see if they can get me one. 

Thanks though.


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## Latole (Aug 11, 2020)

Best is to test the amp before ordering some parts. You may need some more
Power cable is so easy to replace.


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## SmoggyTwinkles (May 31, 2021)

Latole said:


> Best is to test the amp before ordering some parts. You may need some more
> Power cable is so easy to replace.


I'm good. I know what I want to do with it and if I have any issues I know where to find parts etc. 

Wanted to upgrade the reverb tank and speaker asap, but those will take weeks at the least to get here, I'll be putting it back together as soon as I get some free time.


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## Latole (Aug 11, 2020)

SmoggyTwinkles said:


> I'm good. I know what I want to do with it and if I have any issues I know where to find parts etc.
> 
> Wanted to upgrade the reverb tank and speaker asap, but those will take weeks at the least to get here, I'll be putting it back together as soon as I get some free time.


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