Fixing Reverb predicament on HRM'd Traynor YGL-3a

[bcmatt]

UPDATE in March 2014: Skip to the end of the second page to help with the current situation of this amp!

I've had an old 70s Traynor Mark 3 for years, and loved it, but always been tempted to give it some sort of smooth and gainy channel, but was scared to sacrifice it because it is quite a nice amp already. For those of you that are unfamiliar, it's sort of an overbuilt Twin Reverb. The transformers are massive and I actually use it occasionally as a bass amp with an ampeg 4x10.

Anyways, tonight, I just bought another one for cheap. So now I have the guts to try something with one of them.

I'm eager for suggestions, and am wondering if some sort of HRM inspired modification would work. I'm willing to make it just all one single channel amp to accommodate all the controls needed. But first of all, will these transformers provide usable voltages? Mine runs the stock 4 Mullard 6CA7s, but this one I just bought is on some KT88s.

Do you think this would be possible?
Will I be struggling too much to get the tonestack at the right voltages? I'm a complete noob at trying to alter voltages, but realize the ODS tonestack can't just be plopped into any amp with success because it demands some pretty specific operating voltages.
What would you salvage? Like, would it be possible to keep the reverb and tremolo circuits? (I am quite pleased with those on the YGL).

I am willing to make a big project out of this if there is hope of success. The chassis is large and has the great removable top on the head cab (which I love). There seems to be more than enough front panel real-estate and enough 12ax7s without robbing from the reverb and tremolo circuits.

What do you think? Am I out to lunch?

[Structo]

Looks like an excellent amp to mod.
Like you said, massive PT and plenty of room.

Is this a PCB amp? If so are the sockets mounted on the chassis or boards?

[bcmatt]

Looks like an excellent amp to mod.
Like you said, massive PT and plenty of room.

Is this a PCB amp? If so are the sockets mounted on the chassis or boards?

Thanks for the reply.
No, They were made using eyelet boards and chassis mounted sockets. They were meant to be the toughest amps back in the 70s. Someone mentioned ads where they remove the tubes and throw it out a 3rd story window, plug back in the tubes and play the amp. I can take a pic of the inside of the one I already have to give you an idea.

So, would you first attempt just a conversion of the 2 preamps into the HRM; leaving the Trem, Reverb, PI, and Power Sections intact? Or, is that a fool's errand?

[Structo]

I suppose it depends on how much you like the existing reverb and trem.

The PI is a bit different from an ODS. (just resistors and couplers)

I'll bet someone here has converted one of these amps before so they will probably help you out better than I can.

But from what I can tell looks like it should work very well.

[Zippy]

It's been a while since I had a YGL-3A but that was my gigging amp for many years. The removal lid is a wonderful concept - check to make sure the shielding is intact and secure. Does yours have a pair of Celestions in it?

I'd keep the reverb as I think Traynor has one of the best around. I'd also go back to EL34s.

As you note, there is lots of room and the transformers are massive - built for long hours of gigging without breaking a sweat.

Adjust the dropping string for the desired voltages in the preamp. I'd remove the trem, relocate the knobs to your liking, and fab a new face plate.

[bcmatt]

I suppose it depends on how much you like the existing reverb and trem.

The PI is a bit different from an ODS. (just resistors and couplers)

I'll bet someone here has converted one of these amps before so they will probably help you out better than I can.

But from what I can tell looks like it should work very well.

I like the reverb and trem. They are quite nice. I'm not going to say that they are superior or anything, but it is mostly the idea of keeping those features that I like with as little complications possible. (The reverb is sent with an EL84 which I don't think is too common, and I'm assuming that any ODS with reverb posted here is different and would require a different reverb transformer). Of course, it's probably my assumptions that will destroy me.

What would you do regarding the PI? I suppose it is probably an important part of that ODS bloom...

Thanks Tom. You're helping me think this through.

Once a realistic plan is in place, I'll put together the schematic from the two with the features that make sense.

[bcmatt]

It's been a while since I had a YGL-3A but that was my gigging amp for many years. The removal lid is a wonderful concept - check to make sure the shielding is intact and secure. Does yours have a pair of Celestions in it?

I'd keep the reverb as I think Traynor has one of the best around. I'd also go back to EL34s.

As you note, there is lots of room and the transformers are massive - built for long hours of gigging without breaking a sweat.

Adjust the dropping string for the desired voltages in the preamp. I'd remove the trem, relocate the knobs to your liking, and fab a new face plate.

No, mine is just the 3a (head cabinet amp) and the one I just bought was modified from the combo into a head as well.
I was surprised to hear he had KT88s in his, so I'm not sure what all has been changed from stock.

So, you don't think the Trem is worth keeping? There should be enough knobs and preamp tubes available even if I keep it. Or do you think it just won't play well with an HRM?
Typically reverb and trem are the only effects I use in the effects loop, so I figured I could skip the effects loop if I kept these.

Do you have any thoughts on the Traynor PI values?

Thanks,
Matt

[Zippy]

I was surprised to hear he had KT88s in his, so I'm not sure what all has been changed from stock.

So, you don't think the Trem is worth keeping? There should be enough knobs and preamp tubes available even if I keep it. Or do you think it just won't play well with an HRM?
Typically reverb and trem are the only effects I use in the effects loop, so I figured I could skip the effects loop if I kept these.

Do you have any thoughts on the Traynor PI values?

Do you have the schematic? If not, Traynor schematics are available at schematicheaven.com in the Bargain Amps folder.

http://schematicheaven.com/bargainbin/t ... gl3_3a.pdf

If you use trem, by all means keep it. Given that many use the effects loop for what it adds to the color of the amp, I'd rather build that in - but I don't use trem. Your call.

I don't understand your question regarding the PI. Are you asking about original values or whether to keep it stock?

Given the ease of working in the Traynor, I'd start by adding the overdrive and restoring the output to EL34s. If you like what you have, you're done. If not, rework the tone stack. Like it? From my perspective, there's no one perfect HRM so why copy an arbitrary model? See what you and your guitar(s) like.

[bcmatt]

Do you have the schematic? If not, Traynor schematics are available at schematicheaven.com in the Bargain Amps folder.

http://schematicheaven.com/bargainbin/t ... gl3_3a.pdf

Yup. Thanks. I got it; from there as well as from Pittman's TAB.

If you use trem, by all means keep it. Given that many use the effects loop for what it adds to the color of the amp, I'd rather build that in - but I don't use trem. Your call.

I do like Trem, but I have an EH Wiggler pedal that I like more, but I thought I could save having to carry pedals if I kept it in. So, are you referring to the regular passive effects loop, or are you talking about a built in D-Later? Some people even use the regular passive loop with no effects because of what it adds (did I read that once)? The benefit of giving up the Trem is the availability of the tube for a built in D-Later, right?

I don't understand your question regarding the PI. Are you asking about original values or whether to keep it stock?

Ya, sorry. I was just asking if I should keep it as the stock Traynor PI or transfer that over to ODS as well...

Given the ease of working in the Traynor, I'd start by adding the overdrive and restoring the output to EL34s. If you like what you have, you're done. If not, rework the tone stack. Like it? From my perspective, there's no one perfect HRM so why copy an arbitrary model? See what you and your guitar(s) like.

Hmm, that seems like wise advice: One step at a time. I like what you are bringing to the table. So, I guess I should start with trying to fit that overdrive circuit in...

[Zippy]

The benefit of giving up the rem is the availability of the tube for a built in D-Later, right?

Correct.

I don't understand your question regarding the PI. Are you asking about original values or whether to keep it stock?

Ya, sorry. I was just asking if I should keep it as the stock Traynor PI or transfer that over to ODS as well...

From your original post, I'm not confident that you have a stock PI. Best to see what was changed there when the amp was "converted" to KT-88s.

[bcmatt]

You are right. I will have to await the arrival of this YGL that I just purchased to figure out what the exact story is with it.

I had been playing with the schematic for the YGL and adding the OD/HRM.
However, I just opened up the YGL that I already have (late 76 or 77), and realized that there are a few differences.

Anyways, here are some pics of the YGL that I probably won't be modding because it is un-tampered with and has more sentimental value. Plus, it is my first ever amp that I owned, so we will sacrifice this newly acquired one for the mods. It's the fact that I already own this one that I am brave enough to mess with the new one.

But, in case any of you were wanting to visualize what a YGL-Mark 3 actually looks like, here's a taste:

[bcmatt]

Alright, since the amp coming is about a 1974, it has the Master Volume affecting both channels just like the schematic posted earlier.

So, the first trial would be to yank the normal channel and throw in an HRM OD circuit that can switch into the Effects channel of the YGL-3.

I think that I erased and connected the HRM OD in to the right places to make it work, but I would appreciate someone taking a gander at the schem for me.

Significantly, I had to remove the Master Volume that was after the Trem and Reverb as well as any components affiliated with the Normal channel.
Then I interrupted the remaining channel where I guessed was appropriate and installed the OD switch and the Clean Master.

Would it be correct like this?
Is it automatically obvious that certain component values need to be changed around the clean Master?
Also, would you guess that the grid resister values will need to change to something higher or lower on the OD circuit?

By the way, what are the chances that just adding an overdrive circuit like this to an existing amp are going to give me pleasing results? Have any of you guys tried this sort of ODS addition successfully?

I realized that if this circuit works, the control panel can remain the same. I'd be changing the stuff going on behind channel one, but the pot labels for Volume, Treble, Mid, bass can correspond to the OD Level and the 3 HRM controls instead of trim Pots. I'd remove the input jacks and one hole would be the OD switch and the other would be the for the OD Gain pot.

[Structo]

Wow, nice mustard caps!

If it were me, I would probably unsolder the existing board and remove it in case I ever wanted to convert it back to the Traynor.
You never know about the value of these things.

Unless money is real tight, I would make new circuit boards.

[bcmatt]

Wow, nice mustard caps!

If it were me, I would probably unsolder the existing board and remove it in case I ever wanted to convert it back to the Traynor.
You never know about the value of these things.

Unless money is real tight, I would make new circuit boards.

If I do end up going for the full-on conversion to ODS, I think I will keep these boards somewhere.

For this first step of just removing the Normal Channel, I am trying to decide whether to yank the components off the board or to just leave them on with leads taped and curled over the board.
There is likely space to put new board above that end with some spacers.
It will all depend on what I find when this amp arrives.

But, at this first trial, I'll just be looking to add something like this little piece of a board I quickly nabbed from a ceriatone layout. I haven't checked if it is correct yet or anything...

So, Tom, do you think I am wasting my time with the little mods and should go straight to a full on ODS build with these Chassis and transformers?

[Structo]

Hey only you can answer that question.
Depends how much you want to sink into the project money wise.
Lord knows this stuff adds up quickly.

Bottom line, it will always be a modded Traynor so maybe don't go the whole nine yards as far as new boards and all but the transformers are impressive so I'm sure you can get some great tone out of it no matter which way you go.

It's amps like this that sometimes turn into exceptional amps, there are always certain amps where everything just comes together right.
Tolerances, values, wire, etc.
It could be "The One".

But then again, it could be a turkey too.
Ya never know.