# Traynor Guitar Mate YGM-1 Mods and Questions



## ook ook (Jun 3, 2021)

Hi everyone, I have a YGM-1 which I believe is from early 1968, although it could be a late '67 model. It doesn't follow the standard YGM-1 schematic and seems like some sort of YGM-1/YGM-3 mashup. I'd have to take a look at the schematics again but I believe it has a YGM-3 phase inverter and the volume control comes before the tone stack as it does on the YGM-3. It has the 0.1uF coupling cap that people like to swap out on YGM-3s. Tone stack comes after the first preamp tube entirely.

Anyways, the official schematic calls for a 12AU7 in V1 and if I remember right, so does the tube chart on the inside of my amp. When I bought it, the amp had all 12AX7s and it sounded pretty damn good cranked up. Cranking the amp or using the tremolo introduced a high-pitched noise which I figured had something to do with the first preamp tube.

I went ahead and swapped out V1 for a 12AU7 like the official schematic calls for and it really lost the magic. The tube that was in V1 was a 12AX7 labelled RCA, most of the label having faded away. I put this tube in the phase inverter and it did really funny things which leads me to believe that the tube may just be bad. I'm not at home right now but when I get back, I'll be swapping in a new 12AX7.

*If no issues seem present, how detrimental or unsafe would it be to keep the 12AX7 in place over the prescribed 12AU7?*

I get that it's quite the jump in gain but since my amp seems to be a transitional circuit, I'm wondering if it's maybe designed for the 12AX7 and they were simply using up old tube charts.

*If the 12AX7 reintroduces issues, how can I get some of that grind back while using the 12AU7.*

I'm considering repurposing the ground switch as a switchable nfb loop and I'm pretty sure I'm gonna clip the bright cap. Also might replace the speaker at some point with something more British.

Sorry, I have a habit of posting big walls of text most people aren't gonna read. Oh well, hopefully somebody will read it.


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## Latole (Aug 11, 2020)

I work on few Traynor amps, many of them don't follow official schematics.


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## Paul Running (Apr 12, 2020)

Experiment until you find what you want, learn about the operation of each circuit and how each component affects the signal...knowledge and experience may help you gain the confidence to realise the risks of your modifications. Respect electricity and work safe.


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## DaddyDog (Apr 21, 2017)

No issues at all swapping around preamp tubes. Whatever sounds good to you, go with it!

There's a Facebook group called TAO of Tone. You could ask about the schematic there. There's a wealth of Traynor knowledge.


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## ook ook (Jun 3, 2021)

Paul Running said:


> Experiment until you find what you want, learn about the operation of each circuit and how each component affects the signal...knowledge and experience may help you gain the confidence to realise the risks of your modifications. Respect electricity and work safe.


I have been learning about circuits and stuff and I'm careful and knowledgeable enough to not kill myself in the amp. Gotta look into getting proper tools for actual amp work



DaddyDog said:


> No issues at all swapping around preamp tubes. Whatever sounds good to you, go with it!
> 
> There's a Facebook group called TAO of Tone. You could ask about the schematic there. There's a wealth of Traynor knowledge.


I figured the ~5 times more gain might be potentially damaging. I am actually in that Facebook group although I've not posted anything over there. I guess that's my next stop.

I've also noticed that as I turn the reverb up, the tone gets thin. Not sure if that's an issue or if that's just how the reverb circuit in this amp works


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## DaddyDog (Apr 21, 2017)

ook ook said:


> as I turn the reverb up, the tone gets thin


That seems odd. Can't say I've heard of that before. You can do some basic steps like:
1. Try another tube in each of the reverb positions. The schematic will help tell which is the Reverb send, and which is return. But often it is V2 and V3.

2. Try carefully removing the Reverb cables. Clean them with contact cleaner if you have it. When re-attaching at the tank, be sure the outsides of the rca connectors are gripping. They need to be making good contact.

If the tone is still thin, probably time to have an amp tech look at it.


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## dtsaudio (Apr 15, 2009)

Take a look at the YGM2 schematic. It is basically the YGM1 without reverb. The 12AU7 is replaced with a 12AX7. The YGM3 is quite a bit different in the tone stack, and some other subtle differences.
The thinning of the sound when you turn up the reverb could be attributed to a few things. Bad coupling cap from the reverb, noise getting in at lower settings making it seem like it is bassier.
My guess would be that it is an audible illusion. Your are adding far more wet single from the reverb making the sound thin. What leads me to think this is you will notice on the 3, that there is a small 47p cap to ground on the reverb receiving tube.
This acts to stabilize the tube, and prevent oscillation. It is not there on the 1. An oscillation may thin out the sound.
The other thing you will notice is that coming out of the reverb springs to the tube, there is a .0047ufd cap on the YGM1. That cap is not necessary, and has been removed on the YGM3. This will give your reverb much more bottom end.


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## Paul Running (Apr 12, 2020)

dtsaudio said:


> This acts to stabilize the tube, and prevent oscillation. It is not there on the 1. An oscillation may thin out the sound.


Yes and chances are the oscillation is ultrasonic; viewing the signal on a good scope should verify the condition...don't use a low quality scope as it may dampen the oscillation when you probe.


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## Rabbit (Oct 9, 2007)

I have an early YGM-1 that was serviced by " Wild Bill" in Hamilton a few years ago. We agreed to keep it stock with all caps the same or close to original. I had cut the leg of the bright cap which took away a lot of that high end brittle sound. He thought that it would be wise to keep the 12 AU7 in there.But what I like is a fairly clean sound. The one mod he made was to use the ground switch as a negative feedback on/off switch ( like you mentioned) When I picked up the amp I was in a rush to get to Toronto so I had no time to check it out. I said " How do I tell which is which? to which he replied " You,ll figure it out." And he was right .. it gets a whole lot nastier with the NFB out. Your amp may well be different than mine but that is a useful mod!


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## ook ook (Jun 3, 2021)

With the 12AU7 the amp is quieter than my bassbreaker 007 and has almost no drive whatsoever. Also has some strange noise on certain notes. Different from the high pitch noise that I get with a 12AX7 installed in V1. I get the same high frequency noise when I activate the tremolo. I have swapped out V2 and V3 for new tubes and that trem issue still remains. The reverb gets thin as I turn it up still, but there's no real reason for me to go above like 2 so that's not much of a problem, more of a curiosity.

I'm thinking that bringing it to a tech is a pretty good idea. Anyone know a good amp tech in/around Halton Region in Ontario?

If I ignore the high freq. noise with the 12AX7, it really sounds great, but that's probably not the best idea


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## ItsASecret (Sep 25, 2021)

I've got a YGM-1 as well, similar year with a similar quirk: Cranking the reverb will cause the bass to drop a lot. Past 4-ish, it's so thin I'd never even bother using it. I've got the amp open currently and I'm going to take a stab at some troubleshooting this weekend to see if I can find the source of the problem. The RCA cables themselves are pretty rough around the edges so my plan is to give them some love first before I go to far down the rabbit hole.


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