YBA-1 for Torren.

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YBA-1 for Torren.

Postby Racing on Sat May 21, 2016 2:30 pm

So.
Fellow forum member Torren61 wrote me and asked if i could be persuaded to make his old Traynor roar.
I was like..."sure".
Now..a minor issue though was that i live in Sweden in Europe right..and Torren in turn in California in the US. :mrgreen:
That tho..is what shipping is for right! :lol:

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So this thing shows up at the shop of mines doorstep. Seems to have survived the stretch.

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What evolved tho..in all due respect,was a hack job. At least IMO. Some Mr Handyman had been at it before.

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Right. Now..time elapsed since Pete Traynor spawned this thing..well,as it was to be modified i reasoned as such that in that case we could just as well just run the full 9 yrds right.

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So. Operation cleanup. I already from the start swayed vs just replacing most of it and after talking it over with Torren...i was basically given a "carte blanche".
IOW...do whatever the F you want as long as it sound up to snuff vs what you normally do. Ok! Cool enough!

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Yep. Various fuses were to be added. Fuses are good...we like fuses. However..look at that mess in the background. Hm

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Yeah. If there´s one job i absolutely loathe when putting tubers together it´s to put heater wiring down. The more reason to get it done and done in a proper fashion. Tape is simply used to keep the wiring in place as the glue used hardens.

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The stock tagboard got headed for the bin. This there is way more sturdy and way more compact.

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That there solderblob mess needed to go tho...

Idea of mine is to pull a "dual mode" here. Ie;a "basic" preamp where an EF-86 can be added ontop,which in turn sends the entire thing into orbit at will.
EF-86´s tho...

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Yeah. About that.. :mrgreen: . Yup. A whole box worth of the good ol´ stuff.

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A preamp and PI fills that turretboard to the brim. Resistors ontop and caps underneath. Good to go in short.

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In stock form the amp has all in all 4 input jacks. Well,as this is to be turned into a "dual mode" amp we really need just one,but opt to install two so we get "high and low gain" entries.

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Uhu. As per always,turretboard put together flying lead. This just makes for a way more sano install all in all. The centers of the sockets in turn tied together for shield.
About that..these Traynors use some rather peculiar fasteners for the sockets and the ones in there were shot. Getting them out..had to bring to die grinder out,sorry to say.
That was the only viable option.

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Yep. Common rail for shielding. Notice the solder blob...gawd i hate that!

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Input jacks needed a shield too. So. Fabbed this small piece to cater to that.

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Then your basic bias board. Idea of mine here is to collect all things AC,apart from the heaters,to the amp chassis one end. Thus keeping the risk of interference of any kind to a minimum.

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To get all of them solder blobs out of there...took a bit. Picked up a propane driven burner for the task. A small Dremel one.

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Yup. Blobs no more.

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Uhu. Now there´s difference in legislation as well as mains voltage and what not between here and the US. According to law around here a mains breaker HAS to cut both phase and zero. In the US that isn´t really needed as phase and zero is kept apart at the wall,but i reasoned as such that..let´s do it according to the stiffest legislation there is.
That brings that the mains and stand-by switch has been deleted and replaced by that there in turn. Of course we can get into the entire standby or not debate but..let´s just leave it at that.
That there mains breaker coupled with a 3 wire mains makes for one secure and safe manner in which to handle this. In turn running US voltages over here..well,i´ve got me a 10A variac so..no issues.

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...the stock breaker.

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All dressed up and noone to blow huh :lol: .

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Yep. Blobs all gone and reservoir capacitors replaced with 50µF+50µF ones.

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Shield for the input jacks installed in all its glory.

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Hm. Wiring is good,we need wiring. That and the choke...n drop resistors. As you can see i use minor pieces of shrink sleeve to keep wiring together where so called for. Major wiring gauges,like heaters,we keep in check with regular ty-wraps.

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Yes. Doing it the way i do here makes the chassis REAL roomy. Being used to working in way more confined spaces makes it all come together i guess. The trimpot is for heater circuit balance.

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Here we go! Basically all wired up. Lacks the wiring running back n forth for the pots though.

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In essence it´s all there. We do however lack some sort of solder support for what´s needed at the screens and the control grids of the powertubes. I´m giving thought to reusing this old German "tower" as i think it´d fit the overall looks and design of the innards of the amp. In such a case i´ll just drill and tap the chassis for an M5 screw and solder that tower there to that.

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This in turn then the AC side of the amp. The main voltage rectification atop the bias board. Again rather compact,and as you can gather set together at one of the chassis corners.
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Re: YBA-1 for Torren.

Postby Tman on Sun May 22, 2016 10:55 am

Great work as always! :cheers:
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Re: YBA-1 for Torren.

Postby Baron Von Machinenmann on Sun May 22, 2016 12:16 pm

Racing wrote:
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Uhu. Now there´s difference in legislation as well as mains voltage and what not between here and the US. According to law around here a mains breaker HAS to cut both phase and zero. In the US that isn´t really needed as phase and zero is kept apart at the wall,but i reasoned as such that..let´s do it according to the stiffest legislation there is.
That brings that the mains and stand-by switch has been deleted and replaced by that there in turn. Of course we can get into the entire standby or not debate but..let´s just leave it at that.
That there mains breaker coupled with a 3 wire mains makes for one secure and safe manner in which to handle this. In turn running US voltages over here..well,i´ve got me a 10A variac so..no issues.

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...the stock breaker.



I am not a fan of breaking any path to Earth/ground when dealing with the mains on single phase powered amps. The neutral should always be connected directly to one of the primaries of the power transformer, only the line side should be fused and switched IMHO. The third prong should terminate directly to chassis, I usually use an existing transformer mounting screw and solder a heavy ring terminal lug to this.

In reality back at the source panel, ground (green) and neutral (white in the US) both terminate to a ground buss at the bottom of the panel. This is where the power company connects their Neutral and in turn there is a heavy gauge copper cable that exits the box and attaches to a six foot long solid copper ground rod that penetrates the floor and is driven five feet into the sub soil.

Think of the Neutral connected directly to the power transformer primary as a double fail safe, used in tandem with the third prong ground. :2cents: :wink:
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Re: YBA-1 for Torren.

Postby pdf64 on Sun May 22, 2016 4:25 pm

I use a little mains outlet tester at most places I plug in, and it's pretty common to find hot and neutral reversed in the wiring to the outlet.
So if there's a fault inside the amp that results in a short etc between neutral and the chassis, but neutral is actually hot, then if only one side is switched and fused, the chassis will be pulled to mains voltage anytime the amp is plugged into that outlet; the fuse won't blow and switching it off at the amp won't cut the juice.
Hence the benefit in switching (and fusing) both soon after mains enters the chassis.
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Re: YBA-1 for Torren.

Postby Racing on Sun May 22, 2016 7:22 pm

Nah fellas,hold your horses here for a bit.

The amp is converted to three wire mains. In short,AFAIK,neutral and ground will always end up in the same place and ground will always be present-as it isn´t affected by the mains switch.
Now..i may be out on a limb here but i presume that neutral and ground is supposed to share potential in the US too?
If not,please hollar cause then i need to relearn.

That said i´ve fired the thing up.

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I abandoned the idea of that tower and simply went for a cut down piece of turret board. Seing the structural integrity of the 100 Ohm resistors i have no doubt what so ever that it´ll stay put,just using one stand.

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As i´m a true believer in the old saying that one should never let more then two stages use one node...left that i needed yet another electrolyte for the EF-86 up front.
I opted to use an "inxs" piece of board in the case that anyone would ever want to add stages down the road. You never know and it´s always a good idea to think ahead.

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The amp complies with "the golden rule" alright but the PI and preamp hits ground right there. Not to far from the input jack. Speaking of which the ground-s (in the pic) are "floating" in as much that the various needed groundpoints for the PI and "base" preamp are daisy chained and hits the chassis with one wire. In turn the EF-86 setup is the same. Hence all in all two wires.

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Still need to tidy that up a bit,but now you likely get why i opted to use sockets with a "center". In short it´s there to be a grounding point for the grids,and the turret board in turn has provisions to fix each wire routed for it.

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The EF-86 is an old Mullard,then for some Ultron ECC-83/12AX7´s and in turn a pair of old Tfk EL-34´s. Not all that much to add really...the amp works and runs as god intended.
Need to reinvestigate the bias control setup though. It came out to sensitive...just need to redo the voltage divider it represents.

Next up the actual wiring. Ie;the signal wiring.
That and in turn control system. Going to use H11F1´s for that (optos) and it might be that i need to add a small transformer to run them. Future will tell but i expect first roar out of her come tuesday at the latest.

The faceplate will remain,of course,but the actual practical layout of the pots though is another matter...as are a number of add on switches.. :wink:
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Re: YBA-1 for Torren.

Postby Racing on Sun May 22, 2016 7:24 pm

Oh! Forgot!
She came all in,handed 124VAC,at 440VDC@35mA. That made heater voltage end up right on the money btw. 6,3VAC sharp.
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Re: YBA-1 for Torren.

Postby Baron Von Machinenmann on Sun May 22, 2016 9:38 pm

pdf64 wrote:I use a little mains outlet tester at most places I plug in, and it's pretty common to find hot and neutral reversed in the wiring to the outlet.
So if there's a fault inside the amp that results in a short etc between neutral and the chassis, but neutral is actually hot, then if only one side is switched and fused, the chassis will be pulled to mains voltage anytime the amp is plugged into that outlet; the fuse won't blow and switching it off at the amp won't cut the juice.
Hence the benefit in switching (and fusing) both soon after mains enters the chassis.


In the UK, with the high voltage two prongs you use I totally agree. Here in the states, there is a third prong that is dedicated to ground/earth. As long as this is securely connected to the chassis ground there is no issue with this becoming live/hot. I can't believe that high voltage two prongs are still being used over there..... :Zap:
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Re: YBA-1 for Torren.

Postby Baron Von Machinenmann on Sun May 22, 2016 9:49 pm

Racing wrote:Nah fellas,hold your horses here for a bit.

The amp is converted to three wire mains. In short,AFAIK,neutral and ground will always end up in the same place and ground will always be present-as it isn´t affected by the mains switch.
Now..i may be out on a limb here but i presume that neutral and ground is supposed to share potential in the US too?
If not,please hollar cause then i need to relearn.




A picture is worth a thousand words.... :wink:

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Re: YBA-1 for Torren.

Postby Torren61 on Sun May 22, 2016 9:58 pm

This is the first time I've seen this thread. This is me: :excited:

I snagged this 1968 YBA-1 BassMaster from a local CL seller for $100. She had no head cab but she was loaded with three Rogers 12AX7 and two Sylvania EL34 tubes. one of the Sylvania tubes was broken. These amps are bloody LOUD!!! I wanted something a bit different than what this head was. I researched the usual mods but I'm just not 100% on how to do them.

I dropped a note to Pat and also to a VAF member here. He is a SUPER nice guy who will remain nameless unless he wants to be known. He worked with me through emails and pictures and tried his best to explain how to do everything. I'm sure it was a pain in the butt for him and he couldn't help me diagnose a "motorboating" issue. I had an acquaintance come look at the amp and although he's very knowledgeable, he snipped out some mustard caps and soldered new orange drops onto the snipped leads. :cry: The problem remained.

I shelved the head for a bit and cruised the Traynor threads and found this YouTube video. Warning: The dialog is low volume. The amp is HIGH VOLUME. Be ready with your fingers on the volume knob.

https://youtu.be/gms2jhlHQr8

First, I was like: :shock: Then I watched the rest of them and I was like: :not_worthy:

Here are a couple I really like:

https://youtu.be/5OA-UqD9ufE (go to the 3 minute mark)

https://youtu.be/jbxHVojvNRI

I PM'd him and asked if he'd take on the job of finishing and repairing the mods on my Traynor and he said "Sure, but I live in Sweden." Of COURSE he lives in Sweden. :Doh: I did some thinking. :think_1: This amp has some GREAT components, like the transformers for a start. I figured in shipping there and back, labor and parts. Then I watched some more videos of his. It really wasn't a tough call at all. He knows exactly what he's doing and he does impeccable work.

We talked and he asked me what I wanted and who were some of my favorite guitarists. Well... I wanted a really clean amp and one that would get really crunchy and dirty and as for guitar favorites, Page and Brian May would be MY top two. I'm also still working on a Brian May Red Special tribute Tele. I told him he could do whatever he wanted to do. I knew he would put together something unique and high quality. As you can see, Racing does not do things halfway or sloppy. When he told me he wanted to put an EF86 in the preamp section, I was like: :P

When she comes home, my Traynor will not be a Traynor anymore and I'm okay with that. There are plenty more of them out there and when there's one less, the value of the rest of them goes up. I have a custom wenge head cab built and waiting for the chassis. I'm going to have a custom face plate and name plate made. That amp will be named Thor in a nod to my Viking amp god friend in Sweden. I'll post pics when the head arrives here and as the build continues.
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Re: YBA-1 for Torren.

Postby Racing on Sun May 22, 2016 11:46 pm

Baron Von Machinenmann wrote:

A picture is worth a thousand words.... :wink:

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Hm.
Now,i strongly doubt that there´s supposed to be a potential difference between zero(neutral) and ground. That would defeat common sense even.
If we have a zero that has a potential difference vs ground and ground is attached to amp chassis and in turn neutral,in one way or another,sees chassis as reference as well...we have a short. Short as in fuse goes sky high.

IOW what i´m asking is if ground is provided by the main grid or if ground is some sort of physical ditto? As in a ground spear or whatever.?
For the sake of Torren here..we need to get to the bottom of this.
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Re: YBA-1 for Torren.

Postby Torren61 on Mon May 23, 2016 2:09 am

Ground and neutral are the same potential in the US. All neutrals are grounded. I know because I build power lines.
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Re: YBA-1 for Torren.

Postby pdf64 on Mon May 23, 2016 12:32 pm

Baron Von Machinenmann wrote:
pdf64 wrote:I use a little mains outlet tester at most places I plug in, and it's pretty common to find hot and neutral reversed in the wiring to the outlet.
So if there's a fault inside the amp that results in a short etc between neutral and the chassis, but neutral is actually hot, then if only one side is switched and fused, the chassis will be pulled to mains voltage anytime the amp is plugged into that outlet; the fuse won't blow and switching it off at the amp won't cut the juice.
Hence the benefit in switching (and fusing) both soon after mains enters the chassis.


In the UK, with the high voltage two prongs you use I totally agree. Here in the states, there is a third prong that is dedicated to ground/earth. As long as this is securely connected to the chassis ground there is no issue with this becoming live/hot. I can't believe that high voltage two prongs are still being used over there..... :Zap:

Please be assured that the UK has been using earthed / 3 pin ac mains since the early 1930s, see https://en.wikipedia.org/wiki/AC_power_ ... nd_sockets
Grounded domestic type electrical systems, using wall outlets / equipment plugs compliant to BS1363, have been ubiquitous since the 1950s https://en.wikipedia.org/wiki/AC_power_ ... horizontal).jpg https://en.wikipedia.org/wiki/AC_power_ ... 3_1947.jpg
Apologies for any confusion.
Neutral is undoubtedly intended to be at, or at least very close to, ground / earth potential; hence 'neutral'.
The issue I raised is nothing to do with any particular distribution system, or indeed any peculiarities specific to the UK, but is purely down to the mains wall outlet being fitted by an incompetent person, such that the live and neutral wires are reversed at the outlet terminals.
I think that the issue of incompetent persons undertaking DIY electrical repairs, eg replacing a broken mains wall outlet, is likely to be common the world over.
Hence the fusing and switching of both mains and neutral on grounded mains equipment, where the user is likely to be in contact with ground via the chassis, represents best practice.
Also bear in mind that some 'dual converter' type UPS systems create 240V by means of balanced / 2-phase 120V outputs, such that both 'live' and 'neutral' supplied to connected equipment are 'live'.
Also the electrical installations of some high end studios may use 1:1 isolating transformers with CT output with a similar result, to minimise mains hum, following the same rationale as we may be familiar with for heater arrangements.
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Re: YBA-1 for Torren.

Postby Racing on Mon May 23, 2016 9:20 pm

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Back on track then.
That there is a proper James Network,with a few added switches and a 500k linear pot instead of a "separator resistor". If you take a closer look at the small ceramic high and to the right you notice that i elongated its one leg... Well...that´s done with an age old trick from the original book.. :)

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A piece of single strand wire and a small drillbit. You simply grab the one end across the drill with the help of a pair of small pliers and then coil the wire around the drill. The coil left is a surefire way of securing that no matter what the two ends tied together will never fall apart-no matter what,except a full nuclear blast i guess.
A trick used on a regular basis in older amps (read-30´s to 50´s) that were hardwired. Easy to pull off and to the point. As always it´s all in the details isn´t it. :D

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Them coupling caps are rather light why i simply secure them with a dab of Loctites "new" hybrid glue. It simply works wonders...never hardens completely and hence will "follow" any and all movement the head makes. In turn easy to remove and clean up as well.
The whole concept/idea of being able to flip in this case mainly capacitance in and out of a James widens its capacity in a manner it isn´t even funny. Please have in mind that as you change ONE of them the entire James changes how it works...

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The H11 control boards. In the case of this amp i´m going to try a to me new stunt,and that is power them there with a small switched transformer. Going to be very interesting to see what comes out of that,but suffice it to say that it is a newer design that is claimed to work from 100VAC to 250VAC.. Seing the Variac of mine we´ll know soon enough.

That said the amp is up and running and have indeed roared for the first time in its new guise today. Not without issues tho... It turned out that the one 12AX7 i used for PI had one of its triodes shorted out..didn´t notice it at first just reacted to that the amp didn´t sound as it was supposed to.
Replaced the tube but...issue still there. Then notice that the gridleak for the triode in case had taken on a different hue then the opposing one..so guess i´ll replace that 1M resistor come tomorrow.

As is it works though..loud enough,that´s for sure. The unmistakable presence of the EF-86 is there too alright.. :shock: 8)
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Re: YBA-1 for Torren.

Postby Torren61 on Tue May 24, 2016 12:09 am

I feel like a kid in early December watching Santa assembling his Xmas present... :D I laughed when I read "I'm going to try to me a new stunt". Whenever I do that, it usually results in a fire. :dunno:
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Re: YBA-1 for Torren.

Postby Racing on Tue May 24, 2016 7:35 pm

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Nah Torren. We did alright :wink: . That gridleak resistor was shot alright,here the replacement.

That done the amp truly came to life. All good IOW.

Mode control then...
Yeah well,i got to install a switched powersupply of in this case 9VDC. WTF can i say? It simply works. No need for smoothing capacitors,rectifiers or the likes,the thing simply works.
Hooked it up to the mains switch and checked which pin was which outbound as far as polarity. Handed me 9,6VDC unloaded @ 124VAC inbound.
Replaced the series resistors for each H11F for a 470 Ohm one and let her rip. Realized i had forgot ground reference,added that and..done.
In short a productive day and seing what these switched PSU´s run i´m sure going to revisit those..that much is for sure.
Two wires,switches needed to route the voltage,ground reference and that was it. :shock:
If you,like me,are REALLY REALLY anal there´s an ever so slight hum to be noticed at wide open throttle in lead mode,but..then you´re anal. Or put another way put next to your average Marshall you won´t even hear if this piece here is turned on. Only lead will be the pilot light.

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Then for suspenders and a belt. Fabbed this simple shield to aid the controls,or more to the point make absolutely sure the amp is as interference free as they´ll come. Needed? Maybe not,but then again..rather safe then sorry and this little trick makes sure that the caps and what not for the various pots and switches are left alone by any and all "dirt".

Installed a "minor" bright setup for the gainpot ahead of the PI. That..again..made the amp grow even more. 220pF in series with a 56k resistor across the leading legs of the pots.

Done?
Yeah well..might be,for some. As is we´re talking a two channel jobbie of sorts where the "clean" channel (which by any means can be pushed into old school JMP style distortion) CAN hand you a sort of Fender-ish/Vox-ish shimmer alright..and when you flick the switch all hell breaks loose.
However. Stating what i do now we´re into opinion territory more then facts and..being a gigin´ guitarist myself i at least try to get "my" amps to be "magic". After today this one´s on the verge to be...but not quite there IMO.
IOW i feel that i need to invest yet a little more time tweaking the SOB before putting the tools down. Funny part is that it´s already had a few trix tossed at it..and it simply responds a little different then i´m used to when i pull them stunts. Hm.
Well,you live and learn i guess.

Need to pick a few spares up tomorrow..and will take it from there.
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