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December 02, 2022, 12:25:29 PM

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Gorilla TC-110 The Tube Cruncher Amp

Started by Tassieviking, February 10, 2022, 12:13:03 AM

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Tassieviking

G'day everyone
I think I just bought myself a Gorilla TC110 Amp on auction.
I don't know why I did it, it just happened.
I paid $35Au ($25 US) for it so I think I can't really loose anything.
I believe these amps sound crap from what little I could find out on the net.
Does anyone have any circuits or information on Gorilla Amps ?
I read that Pignose made them.
I will have to go and pick it up next week when I go to the city (Hobart Tas)
If I'm lucky at least I scored a reverb tank, 6 knobs. a decent transformer, etc.
I might stuff a 1 channel Sunn Beta pre-amp into the box, just to confuse people.
Or maybe a Marshall Lead 12W reverb, with a nice celestion 12" speaker.
A Schematic would be nice if someone has one.
There are no stupid questions.
There are only stupid mistakes.

Enzo

You can contact Pignose and ask them.

In my experience, I rarely get out schematics for small practice amps like that.  They usually have a 5-leg power amp IC, and one or two dual op amp ICs.

Tassieviking

Thanks for that Enzo.
I'm not sure if it is a small practice amp, it's over 100 Watts and has a 12" inch speaker from what I understand.
But you might be right with the components, the Gorilla TC-35 has one Op-Amp and a TDA2030.
I can't find much information on the TC-110 on the net, I was hoping someone here has some info on them.
Maybe practice amps are bigger then I thought.  :)
There are no stupid questions.
There are only stupid mistakes.

Enzo

No, my fault.  The little photo looked like one of the tiny Gorilla amps I see.  The kind they throw in with a cheap guitar as a "starter set".

A 100 watt amp is more than that.  But I am having a hard time finding a clear photo of the rear panel.  It looks like it says 150 watts next to the 120VAC 60Hz printing   (or 240v etc printing in other lands).  That to me means the amount of power it uses from the mains, not what it sends to the speaker.

You can easily open it up and see what IC is used for the output

Tassieviking

Yeah, the input power to the amp is 150W, 240V here in Australia
I haven't picked it up yet, I'm going into Hobart (Tassie) next week and I will pick it up then.
It looks like I might have to trace the circuit myself when I get it.
If I make a schematic up I will post it here.
For $35 Au ($25 US) I think I can't loose even with a Gorilla Amp.
The photo I posted is from the Auction House I got it from.
It will entertain me for a day or two at least when I get it.  :)
There are no stupid questions.
There are only stupid mistakes.

Tassieviking

Pictures of the amp when I picked it up, it works perfectly, no problems.
There are no stupid questions.
There are only stupid mistakes.

Tassieviking

There are no stupid questions.
There are only stupid mistakes.

Tassieviking

#7
Schematic completed, I don't know if I should post it under "Schematics and Layouts" as well ?
I can't work out what D14 is, the one that is mounted in the heatsink, see above pics.
I have no idea what the Reverb Tank is, it looks like the same shape as the old Folded Line ones.
The Out coil has a Red bobbin. the In coil has a Blue bobbin, resistance DC on schematic.
The only writing on the reverb tank is "26  87  278" on one side. (And Input & Output on other side)
If someone can identify the tank, or a modern replacement, then please post it here thanks.

The Schematic is traced by me and I can't guarantee it is 100% correct, but I think it is.
There are no stupid questions.
There are only stupid mistakes.

Tassieviking

#8
Here are the last files, made with KiCad 6.0.2 , great free program for making up PCB's
Also positioned the pots on the PCB to correct spacing but did not make a PCB up.
Also a scan of the track side of the PCB (Mirrored to help trace components on top)
The scan is fuzzy because it was lifted off the scanner by the heat-sink bracket.

I might keep this amp, in original condition purely to conserve it as an original, if I want to mod it I can always make a copy.
(Apart from the Electrolytic caps, changed them when I had the PCB out)
If anyone can help me with the Reverb Tank identification, or new equivalent type, then please do.
Also if someone knows what D14 might be, please guess away.
There are no stupid questions.
There are only stupid mistakes.

joecool85

Quote from: Tassieviking on February 25, 2022, 04:19:05 AM
Also if someone knows what D14 might be, please guess away.

Overheat protection?  That's my best guess anyway.
Life is what you make it.
Still rockin' the Dean Markley K-20X
thatraymond.com

Tassieviking

Close guess Joe, I think it is for temperature compensation,
It helps with the changing biasing of the power transistors as they heat up (in my opinion), but I could be wrong.
I was actually hoping someone might be able to provide a part number or something to help identify the actual diode.
Its a strange shaped diode, I have not seen many like it in the 50 years I have played with circuits.
Here is a link to the original patent of the idea back in 1966 :https://patents.google.com/patent/US3452281
Some more ideas :https://www.tutorialspoint.com/amplifiers/bias_compensation.htm
It is an interesting topic, but gets too complicated for me nowadays.
There are no stupid questions.
There are only stupid mistakes.

g1

Yes, thermal compensation for the bias to avoid thermal runaway of the output transistors.  With a reading of 1.34 forward v, I think it is a double diode type, which are often seen used for this purpose.

8EB2C1B would be the closest commonly available tank I think.


Tassieviking

Thanks for confirming the thermal compensation g1, I only found out about it when I got this amp.
Apparently it is also common to mount small transistors to the heatsink for the same purpose.

I was also looking at the 8EB2C1B reverb tank, or possibly the Belton BSN2EC2C1B.
The Belton has a different output impedance then the Accutronics when marked as a "C"
Anyway, I am glad to hear someone else thinks the 8EB2C1B tank would be closest as I'm not experienced with reverb tanks.
Thanks for replying.

There are no stupid questions.
There are only stupid mistakes.