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Hey guys, which of the 12A*7 tubes is the one for Reverb & tremolo?
 

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Discussion Starter #3
Me thinks V6
 

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I take it your tremolo doesn't work?
No, all works, reverb bit microphonic.
Wanted to lower to 12AT7 to see how it works.
 

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I lied to you. I just pulled up another schematic and all of V5 is reverb. It's the driver amp. 1/2 of V6 is the receiver and the other half of V6 is tremolo.
I've never tried it, but I don't think 12AT7 will work in the tremolo. I don't think it will have enough gain. V5 may work as a reverb driver, but it is certainly going to be different.
You're not going to hurt anything by trying it.
 

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No, all works, reverb bit microphonic.
Wanted to lower to 12AT7 to see how it works.
I lied to you. I just pulled up another schematic and all of V5 is reverb. It's the driver amp. 1/2 of V6 is the receiver and the other half of V6 is tremolo.
I've never tried it, but I don't think 12AT7 will work in the tremolo. I don't think it will have enough gain. V5 may work as a reverb driver, but it is certainly going to be different.
You're not going to hurt anything by trying it.
Was just about to say: looks like V5 (T7 not X) drives the reverb and 1/2 of V6 (X7) recovers. Trem uses the other half of V6.

https://elektrotanya.com/PREVIEWS/63463243/23432455/traynor/traynor_ygm-3_ygm-4_sch.pdf_1.png

So yeah, do try a T in V5. Now they may have changed the circuit over the years or just decided to stick an X in there in later years to save money (if they weren't using Ts much it would be cheaper cuz they probably got a better bulk price on Xes).
 

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Granny I don't think Traynor ever used 12AT's ?
Microphonic reverb is usually from the recovery side rather than the drive side, as the recovery side has the major gain.
Traynor always used cap driven reverb with a higher impedance tank, so the higher current capability of the 12AT won't get you better drive, but might tame the drive if that's what you want.
On the recovery side, there are tubes that are 1/2 12AX and one half 12AU so you might be able to reduce the recovery and keep the trem working. 12DW7 or the inverse ECC823. In this case you would want the trem (pins 1,2,3) to be AX so ECC823 for this schematic.
 

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I'm sorry, @jb welder is right. Somehow I brainfarted looking at that poor quality schem and thought the 7 was a T.
 

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Sorry to dredge an old thread, but just recently acquired a YGM-4 and the tremelo is not working at all. Nothing straight off the front of the amp, nor through the footswitch jack. Footswitch works as I tried it in the reverb jack and it turns on/off as it should. I noted that all tubes are glowing and the amp is functional aside from no tremolo. Would be nice to have it working, but if it doesn't (or can't without copious $$) then I can live with it for now. The tremolo is the pot to farthest right. I am posting bigger images than I normally do see you electronic experts can see the parts easier.

 

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What test equipment do you have? Are you able to read and translate to the build from the schematic?
One odd thing I see is at the speed pot, the resistor tied to the ground wire and the center pin of the pot. This is not factory, so someone has been mucking about inside the amp.
Also I see what looks like a wire coming off the board. Hard to see, so I'm not sure.
 

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Sorry to dredge an old thread, but just recently acquired a YGM-4 and the tremelo is not working at all. Nothing straight off the front of the amp, nor through the footswitch jack. Footswitch works as I tried it in the reverb jack and it turns on/off as it should. I noted that all tubes are glowing and the amp is functional aside from no tremolo. Would be nice to have it working, but if it doesn't (or can't without copious $$) then I can live with it for now. The tremolo is the pot to farthest right. I am posting bigger images than I normally do see you electronic experts can see the parts easier.

I would re-solder the 3 ceramic disc capacitors to the left near the input for starters.
 

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What test equipment do you have? Are you able to read and translate to the build from the schematic?
One odd thing I see is at the speed pot, the resistor tied to the ground wire and the center pin of the pot. This is not factory, so someone has been mucking about inside the amp.
Also I see what looks like a wire coming off the board. Hard to see, so I'm not sure.
Other than a meter, which I really don't know how to read unless I am following precise instructions. I can't read schematics either. I literally know nothing about electronics. If it isn't something simple, I won't even attempt. I don't want to destroy something trying to repair it.
 

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I will take a look soon and see if it is a cat hair, wire loose, or just long end of something.
 

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Just went and had a closer look. That large disk capacitor, it appears that it was supposed to be attached to that loose wire. The yellow wire that is soldered to panel side of the board where the large disk capacitor is, runs to the trem speed pot. The pot with the resistor solder to the black wire. May be a silly question, but if I can get the capacitor and the wire touching, can I put a spot of solder on there to carry the current? Or is that a ridiculous idea? As I said, having tremolo would be awesome, but not having it for now won't kill me. If I can fix it with all the help here, that's great, if it's too big a job, then I thank everybody for their help and will wait and have it done by a tech, or just find myself a tremolo pedal down the road.
 

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Understood. When it's time, i will post what it is in case a replacement goes by another name, or shape or whatnot. If it doesn't fix the trem, I may just be happy that this little 4x8 sounds far better than I expected.
 

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The pot with the resistor soldered to the black wire, if you read schematics, is this something that is incorrect and can be corrected easily? I tried moving a couple tubes around thinking maybe the tube was too weak to run the trem. They are Phillips tubes, at least the preamps are, so I assume they are original back to 1977.
 
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