Traynor amp hybrid.

[Nixon101]

Been a member for a while, but my first post. I’ve been tossing around the idea of transplanting the power section of one of my bass master yba-1a’s into my custom reverb ysr-1. The custom reverb being the standard traynor 45 watt, while the bass master being the mkii 90 watt version with the huge transformers. Anyone familiar with this amp knows that to get the 90 watts they claimed out of a pair of el34/6ca7, Pete traynor designed this amp to run on a ridiculously high voltage, and a fan in the head cabinet. My first one, when I got it fixed up and running had the plates at 570 some volts with what the wall is pumping out today, I think the original schematic called for around 540. Anyways….. I’m not a tech, nor an expert. I’ve been teaching myself to work on tubes amps for the last 3 or 4 years. I have a few old amps that I’ve refurbished/modded under my belt, haven’t built anything from scratch as of yet although I’ve been thinking about doing that too. I figured my dream amp I would try to design from scratch would just be my custom reverb but louder. It’s loud and clean, did some mods to make it louder and cleaner already. I have a pretty good grasp by now on how these things work but it would just be my first time doing something this extensive. I know other than just straight up transplanting the iron, I’d have to redo the power supply and beef it up to handle almost 600 volts, redo the bias supply, but is there anything I’m missing why this would be foolish to consider? I should also add I want to sacrifice the tremolo tube and add a post PI cathode follower, similar to the sss. Am I being unreasonable to consider this???

[thetragichero]

sacrificing two nice amps for one that might work? i'd pass personally. i like this old traynor stuff so besides a few mods (phase inverter to more marshall values, i prefer 6550s in the yba-1a because i have more faith in them than modern el34-types) they're pretty wonderful as-is

[Nixon101]

sacrificing two nice amps for one that might work? i'd pass personally. i like this old traynor stuff so besides a few mods (phase inverter to more marshall values, i prefer 6550s in the yba-1a because i have more faith in them than modern el34-types) they're pretty wonderful as-is

Ya that’s why I’m on the fence about it too. I don’t like the idea of chopping up two nice vintage amps to make one. But it would be perfect for what I want. The custom reverb is far from the bass master. Doesn’t break up much like a bass master, think loud and clean like SRV. Especially through a 2x15” evm loaded cab. Which is what I’m after, hence adding the sss phase inverter. The yba-1a would be the doner to the ysr-1 which I want to beef up. I have another yba-1a which I’ve modded to somewhat close to Marshall bass spec. This second one I got a good deal on, I figure it would give me a winter project.

[thetragichero]

i should qualify that i was by no means being critical. i am the kinda fella who gets really psyched about new projects and that peters out when a major roadblock occurs, so i have many builds in various stages of completion (many do *eventually* see the light of day, but i certainly work better when i have a deadline) so i could see worst possible case is that you go from two very nice (i REALLY like the traynors, down to being able to access the chassis by removing four bolts an pulling up instead of having to take a heavy metal thing out and find a way to prop it up so that the tubes don't get crushed or melt something. and the schematic stapled to the inside is super neat from a maintenance aspect) amplifiers to two partial chassis because a transformer doesn't fit nicely or something. maybe i'm too pessimistic

[sluckey]

Before doing a transplant try this easy experiment. Set the amps side by side and patch the custom reverb ysr-1 preamp into the bass master yba-1a power amp. If you like what you hear you may want to install preamp out and power amp in jacks on each amp. Then you can easily patch just using an instrument cable. Carry both amps with you. Give your roadie a raise.

[Stevem]

The fastest way to more cleaner volume/ SPL level is more efficient speakers, more speakers or speakers with a larger cone area , or a combo of all of these.
Transformers are getting damned expensive these days where as the price for good used speakers should you choose that route has not.

A increase from 45 watts rms to 90 will not buy you as much clean head room as you may be hoping for!

[Nixon101]

Ya I think I have the whole lots of big efficient speakers thing in spades. And I definitely don’t need a louder amp. I just play at home. Not in a band. But what I like almost as much, maybe actually more than actually playing guitar, is working on amps. I want to do this just for the experience, and to learn from it. I could always just build one from scratch like I said, which I still want to, but what I would build would just be these two amps together anyway. I want to do it just cause I can, not cause I need it. Trust me the only thing that might hold me back is that fact I don’t like the idea of hacking up two nice old amps. But I’d just like to know anyone’s opinions on how feasible this might be if I were to do it. Any more technical feedback would be appreciated. And you guys saying don’t do it….. trust me I hear you guys too, I likely won’t, but what if?

[Reeltarded]

Where are you getting power for this direct coupling?

You should buy a 100w amp and fake the rest. It really isn't the headroom you imagine. That is the major point. It's like the guys who spend an hour and money to make a half power thing, then they realize that the half of the power that is left is almost all of the power.

3db isn't room to stand up.

I like sluckey's line out idea, except I would drive a huge class D amp and hurt someone.

[Nixon101]

Trust me, I know twice the wattage is not twice as loud. I know what kind of clean headroom to expect out of this. I’ve already stated my reasons for wanting to do this, and reasons why I’m skeptical. Although I’ve played a 45 watt bass master next to a 90 watt bass master, and I think you’d all be surprised. Between you all saying it’s useless, to me tooting the horn of the 90 watt power section of a traynor amp, truth is, it’s probably somewhere in the middle. If it was useless the yba-1a wouldn’t exist.

I’m not sure I know what you mean by “where am I getting the power for the direct coupling?” I feel like your just asking me to gauge my aptitude by the answer I give, and I get it, I do it too. Especially since I’ve already proclaimed I’m a noob just getting into the hobby. (Well 3 or 4 years ago but my first time doing something like this) I assure you my answer isn’t “duh, from pluggin it into the wall!!” Id appreciate to hear your concern in a technical fashion on why this might not work. I realize a very complex bias supply must be built and tuned. But what else??? I think the power transplant is the easy part and the ppicf the hard part.

[Colossal]

I’m not sure I know what you mean by “where am I getting the power for the direct coupling?”

I think he means, you will need a dedicated bi-polar power supply to feed your cathode follower drivers. Martin Manning designed a Class AB2 driver circuit which is posted on the forum; just search for it. I recently implemented it in an ultralinear bass amp build and it worked very well. You get a huge amount of punch and clarity with the driver. Anyway, I added a 160-0-160VAC winding to a custom transformer to supply the driver circuit.

[martin manning]

Anyway, I added a 160-0-160VAC winding to a custom transformer to supply the driver circuit.

It'd be easy to create the bipolar supply from the YSR-1 bias winding, no so for the YBA-1a. That circuit is also posted. A small flat-pack transformer could be added for that.

PS, I would feel bad chopping up vintage amps too, FWIW.

[Nixon101]

Now we’re talking….. I’ve definitely read those threads, and all related threads before. My thoughts for using the bigger iron was to boost wattage at the same time too. Also I remember a discussion/questions whether a dedicated bias winding would supply enough current. I know a typical bias supply there not much at all current demand, but haven’t really found a definitive answer to whether this type of bias supply needs a certain amount of current capabilities. I’m not to keen n added another separate transformer. I know In the sss, the positive supply was from the normal b+ string, and the negative bias supply was drawn from one leg of the hv secondary, like a lot of other amps out there, like the Yba-1a. Also wasn’t there a reason why the sss needed something like a couple hundred negative volt supply? I wouldn’t get that from the ysr-1 bias supply unless I built a voltage doubler, but then the current capabilities diminish, which I’m still not sure how much I would need. Appreciate the feedback

[martin manning]

The quadrupler (back-to-back doubler) supply is here (.pdf on pg. 2): https://tubeamparchive.com/viewtopic.php?f=4&t=29882 It works fine when powered by the typical Fender 60V bias tap. The dedicated winding in your YSR-1 should work fine if you went that way. Using the YBA-1a power supply you can derive the negative voltage from the HT like SSS 002, but you end up with very high voltage from positive to negative

[Nixon101]

The quadrupler (back-to-back doubler) supply is here (.pdf on pg. 2): https://tubeamparchive.com/viewtopic.php?f=4&t=29882 It works fine when powered by the typical Fender 60V bias tap. The dedicated winding in your YSR-1 should work fine if you went that way. Using the YBA-1a power supply you can derive the negative voltage from the HT like SSS 002, but you end up with very high voltage from positive to negative

Is there any reason I can’t run the plates of that cathode follower tube further down the high voltage string, like after the first preamp triodes, to knock some extra voltage off? I have experimented before with running multiple consecutive stages off one node and found more than two creates a lot of noise. I remember reading a technical explanation for that but can’t quite remember at the moment why. Being that there would be the phase inverter between these stages, would they be properly, de-coupled so to speak?

[martin manning]

I don't think that is a good idea. A better way would be to add an R-C branch off the screen node and drop some voltage with that.

To see if it's really the power amp that makes the difference, I like sluckey's suggestion to swap the pre and power amps using a jumper. Much less effort to try it out. If that does it for you, and you are just playing at home (you won't be hauling two amps around), you could arrange a convenient pre amp out/power amp in using the extension speaker jack locations. The signal path break point is in front of C7 on the YBA-1a and in front of C12 on the YSA-1. The YBA-1A also has a cathode driven Fender/Marshal type tone stack that might be a significant part of the difference too. BTW it looks like the R18 and R19 are miss-marked on the YBA-1a schematic, likely 470k not 47k.