Traynor YGM-3 (early) - Selmer cab

[Barks]

Hi All,

I have been invited here by a good friend to help get my old amp to a better place.
I am based in Leeds UK - so my outlet will be at 240v
I am a relative novice to the finer details but have a good head for safety and have "maintained" the amp more or less myself over the time I've owned it - but here to also learn.

Here's the story so far - forgive me if this is TLDNR - but I am going to be as thorough as I can.

THE GOOD

It is a late 60's (think 68-69) Traynor YGM-3 Guitar Mate Amp.
It has always been installed into the carcass of an early 60's Selmer Thunderbird Twin 50 since I got it over 20 years ago.
I do not know who cobbled it all together - but it is kinda genius!

The Selmer still has the two original Goodmans 2x12s.

The Amp
[IMG:702:454]http://i650.photobucket.com/albums/uu222/katbarks/Traynor%20-%20Selmer/Traynor%202.jpg[/img]
[IMG:721:532]http://i650.photobucket.com/albums/uu222/katbarks/Traynor%20-%20Selmer/Traynor%201.jpg[/img]

A variable midboost was added in the late 90's.
Based around a wahwah inductor, it helps the amp have a bit of beef with Strats.
I keep it off for the Les Pauls.
The power switch was removed from the rear panel and placed on the front.

Front Panel
[IMG768]http://i650.photobucket.com/albums/uu222/katbarks/Traynor%20-%20Selmer/IMG_20150508_132952531.jpg[/img]
[IMG768]http://i650.photobucket.com/albums/uu222/katbarks/Traynor%20-%20Selmer/IMG_20150508_132957810_HDR.jpg[/img]
Mid Mod: Inductor and new pot by Volume Control:
[IMG768]http://i650.photobucket.com/albums/uu222/katbarks/Traynor%20-%20Selmer/IMG_20150508_133226018.jpg[/img]
Original Tone Stack across Bass and treble Controls
[IMG768]http://i650.photobucket.com/albums/uu222/katbarks/Traynor%20-%20Selmer/IMG_20150508_133246586.jpg[/img]

Recent mods:
I have recently been on a journey of discovery and done some well known but simple mods (Thanks to Pat Furlan and his youtube videos)
My good mate Stew of Xaudia Mics in York helped me here as he had some mustard caps.

First - bypassing the presence cap.
I made mine variable via an On-Off-On switch.
Now its Original, Off and Intermediate.

Please excuse the "joke" for the presence switch:
[IMG768]http://i650.photobucket.com/albums/uu222/katbarks/Traynor%20-%20Selmer/11148525_10153291625351147_8673277525480793679_o.jpg[/img]
[IMG768]http://i650.photobucket.com/albums/uu222/katbarks/Traynor%20-%20Selmer/11312918_10153291624246147_4270762737707427711_o.jpg[/img]

Second - replacing the first 0.1 coupling cap to a different value.
We tried 15nF which moved it from 8Hz to about 60Hz.
[IMG768]http://i650.photobucket.com/albums/uu222/katbarks/Traynor%20-%20Selmer/23044ed5-8376-4d60-aec4-7157051fcfa6.jpg[/img]
I've since changed it for a Mallory .01uF to move the filter point to 80Hz.

Third - changing the stock Brite cap across the volume control to 120pf from 1000pf.
Sorted the hiss and made the treble control more fun - but I may revisit this and go for 330pf.

So far so good!
It is tightening up and sounding great - less flub and not so shrill and the tone circuit is a lot more interesting.
I've always loved this amp and now it's getting more interesting. WinWin

THE BAD

This amp does NOT have the correct Power Transformer

The power voltages are out of whack due to this nondescript PT.

Filament is at 7.5V ac
Plate voltage on the power tubes is 456 Vdc
I found from some research - but could be wrong! - that these old EL84 Traynors were supposed to run over 400V?

When I was gigging regularly (before Dad duties came along) I would be replacing the Output tubes every 6-9 months as they would start to get dull.
My tech at the time pointed out that they were pushed hard by the incorrect Power Transformer.
One day it'll sound amazing for a few seconds he said "then go boom!"

Here it is on the chassis. There are no identifying marks.
Looks kind of like an old Marshall type?

[IMG768]http://i650.photobucket.com/albums/uu222/katbarks/Traynor%20-%20Selmer/IMG_20150508_132858655.jpg[/img]
[IMG768]http://i650.photobucket.com/albums/uu222/katbarks/Traynor%20-%20Selmer/IMG_20150508_132911591.jpg[/img]

Here are the wires inside.
Green for the 7.5Vac pictured on the left. The rest just above the board to the right. Circled
[IMG768]http://i650.photobucket.com/albums/uu222/katbarks/Traynor%20-%20Selmer/8ab8eb76-ef28-494f-8da5-6f94e868dd6c.jpg[/img]

There is also a Brown and Green wire (circled pink) coming out from the PT that are soldered to points on the board - but left unconnected.
Brown measures 42Vac
Green measures 21Vac
[IMG:768:1024]http://i650.photobucket.com/albums/uu222/katbarks/Traynor%20-%20Selmer/ca834dad-331e-4b27-bdda-76a953fef18b.jpg[/img]

I think the time has come to get this sorted and make the power side more to stock as I'd hate to lose this fella.

Any help greatly appreciated - and again apologies for the long post!

Barks (UK)

[cbass]

A bucking transformer might be a solution for the high heater and b+ voltage.
http://www.geofex.com/article_folders/v ... ntvolt.htm

[Phil_S]

A 10W 0.25Ω wire wound resistor in series between the PT and the first tube should drop about 1V and get your heaters into the right range. It will get hot. Place it where it can shed the heat. If that doesn't turn out right, try 0.5Ω.

[Reeltarded]

^^^ another great suggestion Cbass.. Barks has been eating tubes and light bulbs.

(nom nom)

The B+ is high but the filament is killing it. I suggested a resistance added to the heater legs. There are other people with similar supply voltages though..

Poor lil 84s!

[Barks]

Thanks!

I can get a 10 watt 0.22 tomorrow so would this suffice?

http://www.maplin.co.uk/p/wirewound-10- ... stor-h0.22

there is also a 0.47 in the same range.

Seems to be a lot of room on this side of the chassis so i could figure out a way of mounting off the chassis about an inch or so.

It also eats the pilot bulbs, so could I fix a similar resistor in series here too?

cheers

Barks

[cbass]

If you could find a 12-0-12 tranny it wouldn't have be but 1.5 amps being its 240v and all .
That would knock noltages down approximately 10%

[Reeltarded]

10w 1R and .5R are what you probably need.

The light (not looking at pics) is running off the heater taps.. so once you have the series resistance the lamp should be fine. (unless there is something I don't know about)

I wish my amps looked that legit.

[cbass]

You can certainly knock down the heaters with a resistor. And it dedinately needs knocked dow .But what about the ht ? I don't think any modern el84 is gonna be reliable with over 450vdc on the plates .

[Bob S]

^^^ +++ what the guys said first.
When you get the filament voltage to a reasonable level I wouldn't feed it new production 84s. Plate voltage that high will snap, crackle & pop very quickly. 6P14P's will take it if you don't want to spend the extra on nos euro 84s.
Nice amp.

[Stevem]

That amp will never sound anything like it was ment to with the B+ voltage being 56 volts too high, putting aside killing the output tubes!
That power transformer is far too massive for that amp!
A power transformer with 3 amps of heater current and about 125ma of secondary B+ current is what you need!

[Stevem]

That amp will never sound anything like it was ment to with the B+ voltage being 56 volts too high, putting aside killing the output tubes!
That power transformer is far too massive for that amp!
A power transformer with 3 amps of heater current and about 125ma of secondary B+ current, and a 290/290, or 300/300 voltage output will do you nice!

[Barks]

Thanks for the help so far!

ok here comes the newbieness...:/

Ive found this type from Farnell which has other values:

http://uk.farnell.com/te-connectivity-c ... dp/1259291

As it has been mentioned that these will likely get hot, I like the idea they have some form of heat disipation and mounting points.
I could make a bracket/standoff that has them "securley" floating in the chassis, thus allowing air circulation.

Does it look appropriate? Im not sure I understand the temp coefficient rating

[martin manning]

What are you looking to do here Barks? A bucking transformer set-up would be good for a vintage amp which you don't want to modify, but that's not the case here. It'll be another piece of gear to lug around and hook up, unless you built it into the existing cab, where it would just increase the weight.

I think I would replace the PT with something closer to the original, voltage-wise. One possibility which might be available in the UK is a Hammond 370EX, which has 275-0-275 HV secondary at 144 mA, and 6.3VAC at 4A, with 120/240VAC primary. This would probably yield around 385V on the plates at idle conditions. http://www.digikey.co.uk/product-detail ... ND/3869588
(edited in link to UK supplier)

[Barks]

Hi Stevem,
thanks so much for the input!

It seems the choice is to fudge the voltages down or replace the Tx alltogether.

At this point i wouldnt know where to start sourcing a new PT in the UK, so any pointers would be great.

I will say though that it is obviously a tough old bird as it has been hammered by me over the last 20 years - still functioning and does sound great.

Any help is greatly appreciated whilst I develop my understanding.
I know my limitations, and it may be I may be that I have to source a regional amp guru to help out if need be.

[Barks]

haha, I cannot keep up with you guys posting!
Thanks!

Martin, I think the replacemnt TX will be the correct path.
It may be a little beyond me to do myself, though it may be a good learning cuvre.

This btw does have evidence that it was a 240v import on the back plate for the UK market and not an amp somebody tried to fudge. Traynors are rather scarce here - and its always been cool to be differnt with this fella.