What to build with a Baldwin 512-025947 OT(Matchless Clubman)

[frankenxtein]

Just slinging together a few things to build another monstrosity. 

I haven't got a schematic worked up yet but , hoping to use the Baldwin output transformer from a organ amp.

Parts:
Thordarson 26r46 - 370-0-370vac 190mA 5volt 3A two 6.3volt taps 7.9A & 1.2A It is in the 1966 catalog. Weighs over 11lbs

Baldwin OT 512-025947 -  20:1 ratio 3440k with a 8 ohm load 3.5" tall 3" wide 3.5" bell to bell , about 3lbs. (used 4 el84' PPP) I don't have a schematic of the Baldwin 46H but , they could have been using it at 4 ohms. So a 16 ohm load is probably not a good thing. What I've read it's a 40watt OT but I'm not trying to hit a certain output.

Baldwin Choke B512-024873A .... 8H 169 ohms (if needed)
1- 5u4gb RCA
2- el34 Shuguang

I was hoping to put a Bassman style preamp on the front of a power amp made with the above parts?
        I realize the PT has a bit more voltage than required by a Matchless Chieftain. That design is a bit more complicated than I had in mind. Any suggestions on a cathode bias design , that would fit the iron would be appreciated. 

[TIMBO]

JTM45 with cathode bias EL34

[frankenxtein]

JTM45 with cathode bias EL34

Thank you ...... There are lots of variations with that it seems looking through the interwebs. Marshall schematics are laid out a bit different than Fender. https://robrobinette.com/5F6A_Modifications.htm

[DummyLoad]

how i'd experiment with that combo: run the OT at 16 ohm for reflected Z of around 6.8k Ra-a, use 5U4GB recto, EL34s cathode bias in AB1; Rk would need to be around 470R shared. use 1k 3w screen resistors.  - should make ~40w. sim shows you'll be around 440V B+ to the plates with a 5U4GB, use the choke and no more than 47-50uF for the plate (first) filter. until the rectifier output tubes warm up you may see over 500V to the first and second filters. you may wish to stack a pair of 350V 100uF for the plate filter. or use 600V MIEC filters.



--pete

[frankenxtein]

Thank you Pete , I can do that. 16 ohms puts it well inside the 190mA of the PT spec. I see Studio Electronics is up on eBay .... I'll have to do some figuring on what space vs cost is. Those first caps will see a bit more voltage than my previous build which just bumps up to 500v. Just no escaping the cost on those caps it seems

     Was planning on putting this in a the same chassis 13 3/8" x 7 1/2" as my other amps. I may just make a heavier longer chassis for this one. Planning on a point to point with tag strips. 

Didn't mention the B512-024873A choke is 2.75" wide 2.25" tall 2.75" bell to bell. maybe  1.5lbs For those of you that are interested    

[shooter]

+1 for the 34's self biased, I stole mine from a clubman, don't bother with the MV - brilliance circuit.  I don't use NFB, and I run a lower B+ ~ 380v for around 25-30W

[frankenxtein]

I was looking at 5-12-01 JTM45 schematic.  Is that the Matchless Clubman your referring to ? That looks simpler , I can do that one  Did you use that 6SH7 tube? I'd like to have that effects loop for sure.   

Ordered MIEC  2- 33uf 600v , 2- 16uf 500v (thanks again Pete) , I have a few 22uf 450v

Just ordered a 6sh7

[shooter]

Is that the Matchless Clubman

yup, but I just used the PA section, I used and inter-stage tranny for the PI and a blended version of Dougs blues Jr and Steve Hess's(?) plexi for the pre

[DummyLoad]

I was looking at 5-12-01 JTM45 schematic.  Is that the Matchless Clubman your referring to ? That looks simpler , I can do that one  Did you use that 6SH7 tube? I'd like to have that effects loop for sure.   

Ordered MIEC  2- 33uf 600v , 2- 16uf 500v (thanks again Pete) , I have a few 22uf 450v

Just ordered a 6sh7

i've read about concerns using the 6sh7, e.g., that it's just too unstable and noisy, however, YMMV. later versions of the clubman use the 6267/EF86. even the 6sh7 datasheet warns against use for audio. IIRC HBP has/had one, hopefully he'll chime in with some advise. +1 on the omission of the cross-line MV and brilliant controls: they suck on the DC30 as well - yes, i built one... ;-)


--pete

[frankenxtein]

I was looking at 5-12-01 JTM45 schematic.  Is that the Matchless Clubman your referring to ? That looks simpler , I can do that one  Did you use that 6SH7 tube? I'd like to have that effects loop for sure.   

Ordered MIEC  2- 33uf 600v , 2- 16uf 500v (thanks again Pete) , I have a few 22uf 450v

Just ordered a 6sh7

i've read about concerns using the 6sh7, e.g., that it's just too unstable and noisy, however, YMMV. later versions of the clubman use the 6267/EF86. even the 6sh7 datasheet warns against use for audio. IIRC HBP has/had one, hopefully he'll chime in with some advise. +1 on the omission of the cross-line MV and brilliant controls: they suck on the DC30 as well - yes, i built one... ;-)


--pete

..... oh well I saw that  but it didn't stop me from getting one for my tube museum. Lots of reading to do , not finding a schematic with that EF86 in as a substitute for the 6sh7 .... yet. http://el34world.com/Forum/index.php?topic=11691.0  The MV Brilliant controls can just be left out?

Ahhhh here's one with the ef86 https://www.dropbox.com/s/n6am2ux5kercysi/clubman3596.jpg?dl=0

[DummyLoad]

The MV Brilliant controls can just be left out? yes.

looking at the schematic you posted: clubman with EF86 uses same values for bias scheme as the matchless DC30 EF86.

--pete

[frankenxtein]

The MV Brilliant controls can just be left out? yes.

looking at the schematic you posted: clubman with EF86 uses same values for bias scheme as the matchless DC30 EF86.

--pete

Thank you Pete & Shooter for your help this will be a fun one. I'll get a marked up schematic posted asap. Those first two caps will be 33uf 600v as usual it will be a bit different than original but , close enough.

Anyone with one of these Thordarson 26R46 PT's that isn't tagged is in for a surprise. You'll want the VOM to check continuity. Don't assume anything really has meaning on this one.
         The color codes are really odd and unconventional except for the primary. Then when the PT is 50+ years old , the colors are often faded to boot. With 116vac on the primary 386-0-386 , 66ohms across 33ohms each leg of the HT. The center tap is not the striped one of the three faded wires  It doesn't end there the 5&6.3 volt winding's are a solid and a stripe. The high amperage 6.3 volt is heavier wire that the low amperage 6.3 volt.

 Primary -Black & White with Black stripe

5Volt- Red (almost orange) & White with a black (almost blue stripe)

6.3 volt (the high amperage) Yellow & Yellow with a green stripe (heavier wire)

6.3 volt low amperage Green/Blue & Yellow with a blue stripe

HT&CT - Faded brown maybe and the same with a green stripe. One of those faded Browns is the center tap , the one with a green strip is one of the HT leads.

Whites look yellow , yellows look beige , blacks look blue , so ....... reds look ......

I'm sorry I don't want to open up the transformer it's not broke No humming .... not like I'm going to put my ear near it.

Yeah I didn't check it before I started this build ..... I have a lucky fuse.

[frankenxtein]

Going with the schematic for the Cubman 3596 See post July 08, 2017, 08:06:42 pm
except changing ...... First two filter caps are 33uf 600v , the other three are 16uf 500v.
Will leave out the MV & Brilliant controls as suggested. Everything else , will go by the schematic that kagliostro had posted for someone , thank you Franco 

here's another thread http://el34world.com/Forum/index.php?topic=15219.0

 

[frankenxtein]

Running all this mature iron with my Bucking transformer to get proper 5v & 6.3v lowers the B+ to spec , usually lower. 5u4gb seems to really help. Still very much a novice but , just trying to have some fun.
Going to Lowes to get a piece of steel 12"x18" 16ga to form a "C" shape chassis for this one. Want a little longer/heavier chassis than my previous build. Making end caps out of a piece of angle .....

All input appreciated 

[frankenxtein]

Got a chassis made 18"x7.5x2" (Steel) Trying to figure out mounting the iron. 

[frankenxtein]

Still trying to decide the transformer orientation. This has really put the brakes on my project. X mounting the PT would give me more room underneath. 18"x7.5"

Would the arrangement Platefire used on his Hot Shot 48 
Mine is tube rectified , less filtering , my choke being X mount on the long side (Platefires is short side X mounted)

Platefire is using a Solid State rectifier , choke loaded , turret board , 8 1/4" x 22" chassis ,

See Page #3 http://el34world.com/Forum/index.php?topic=19557.100

[TIMBO]

Spin your OT 90 degrees, plate wires on your right.

[frankenxtein]

Spin your OT 90 degrees, plate wires on your right.

Plate wires ? you mean the wires out of the PT toward the outside edge?

[frankenxtein]

Spin your OT 90 degrees, plate wires on your right.

Plate wires ? you mean the wires out of the PT toward the outside edge?

Sorry I missed that lol "OT"

[frankenxtein]

Thank you 

[brewdude]

I'm no expert, but I would be inclined to rotate the PT 90 degrees and slide the rectifier and PA tubes down towards that end. 

[sluckey]

I'm no expert, but I would be inclined to rotate the PT 90 degrees and slide the rectifier and PA tubes down towards that end.

I agree.

[frankenxtein]

I had  another pic of that but the choke is on the outside.

[frankenxtein]

No rush on punching holes yet

Going to work up a .sch file on this amp from the DC30 .sch.

Wondering if possible to add switches to the MV and Brilliant is a thought. I have a friend that likes those.

Also he suggested changing the effects I/O to something solid state.

The 1k 25w resistor is also of interest.

[frankenxtein]

Well I've got almost all the wholes punched for my left hand Mangler/Marshall/Matchless 

It's not the first time I've done that left handed mistake    I was going with my usual input/volume  right next to V1 and well then it was too late. Going with valves in the back  Iron in the front. 
It's laid out like a Marshall JTM45  as far as the Iron and tubes go ah but it's a mirror image lefthander  .... I needed another one.

I've got a DPD switch to bypass MV&BRT after the .047 coupling caps?

Plenty of room in the preamp area put the holes for I/O close to the ef86 in the back next to V2.
Got plenty of nice shielded wire from the umbilical of the Baldwin 46H.

All that's left to drill are the tag strips and a de-burr 

[frankenxtein]

I had  another pic of that but the choke is on the outside.

Although I cut a big hole to Z mount the PT , I covered it up and will go with mounting it up top. Been a bit under the weather just getting back to this now.

[frankenxtein]

  Not sure if I got this ef86 right ?  The pins that is

[DummyLoad]

pins are correct.


--pete

[frankenxtein]

pins are correct.


--pete

Thank you Pete

The Matchless Clubman 35 PDF (6sh7) doesn't show that 1K 25w resistor on the screens. Just the two  1K 12w

Could it be they didn't use a choke? In the ef86 version schematic. All my changes are in RED (Iron and the filter caps) There wasn't a value entered there for the choke on the 3596 drawing.

The Nightclub Guy sch moved the 220k resistor to end of the filter chain. In the other two drawings it's the first resistor but the V1 comes out at a different place.

Three drawings lol all different in the power supply?  I started at the other end (preamp) 

If I would have looked at the Nightclub Guy version .... they noted those pins on that ef86

Engineering the shock mount for the ef86 was an afterthought here. Using bottom mount sockets has it's advantage though.





 

[frankenxtein]

Since I'm not overly experienced , I have to do a lot of reading. Trying to shoe horn stuff together is always a challenge but I've got nothing better to do.

Rather than mess with a big 212 cabinet to get my 16 ohm load or smaller 210 ..... I've found a PRS 50 watt 16 ohm speaker for $40. Used with their Sonzera 50 (http://www.prsguitars.com/index.php/amplifiers/sonzera/sonzera_50_combo_head)

I have a few smaller OT's that would put me inside the 8 ohm speaker load but want to stay with this larger OT. Maybe one day I'll figure out these VVR circuits to knock a lot of voltage out of one of these power transformers?

I'm trying to stick with the specs on the parts in most of this , my layout is more JTM. Not sure what this will sound like but , leaving spots to change things.

I have a 1k 25watt resistor but , I'm only seeing that with the Clubman 35 , drawing I marked in red for showing what iron I'm using etc. So unless there's something I'm missing that wont make it inside? I'll be going by the Nightclub Guy drawing sans the bypass on V1 and the Bright switch on the Volume control after V2. Maybe a few other minor differences. 

In my search for component values I came across this ef86 circuit


 

 

[frankenxtein]

Well it don't work  Voltages are close to what the clubman3596 schematic shows (Nightclub guy schematic for the power supply part)

 I get no sound.  Bypassing MV/BRT controls completely , Direct from volume control to PI

Using a small amp I'm able to get sound thru the power tubes , but not thru the phase inverter or , anything ahead of it. 

Should I be able to get sound with my little amp thru the phase inverter input  .1uf capacitor?

I checked it against the schematic and it's all built as shown. 
Before I change anything.

I don't have an extra ef86 (pin#1- 88v, pin#3- 2.v,  pin#6 104v) and I've swapped out everything except it and the power tubes (417v plate 408v screen 29v cathode).  Cathode resistors 360 ohms ea.

[frankenxtein]

PI voltages
1- 302v
2- 53v
3- 78v
6- 292v
7- 50v
8- 78v

[pompeiisneaks]

Do you have a scope?  If so you could input a small sine wave and trace it through the amp seeing if it's getting past each stage.  If not, you could input a sine wave, and get a multimeter set to AC and measure the voltage before and after the stage and see that you get magnification in each step, if there's no AC after the coupling cap, that stage may be losing the signal or dropping it lower etc.

~Phil

[frankenxtein]

Thanks but , no I don't have a scope.

I just built another probe to pick up a signal. http://billmaudio.com/wp/?page_id=1254

Love those 9v powered amps.

I'm gonna chase it , thanks for the tip. I was approaching this backwards.

[frankenxtein]

 Signal stops at the PI input


5751 V1 .101 mv in .32mv out
ef86 v2 .113 mv in 27.5v out
12ax7 v3 5.39v in .003v out

Maybe the input capacitor on the phase inverter bad or , too big?

[pompeiisneaks]

Bad, possibly, too big, not an issue, it just changes what frequency response is allowed through, but it doesn't block the signal.  It could also be the previous stage tube itself having issues, or any of the other related components around it, like the cathode resistor, cathode cap, but definitely narrows it down for you.

~Phil

[pompeiisneaks]

Looking at the schematic, I do think you s hould double check you have signal at several spots after the EF86.  (maybe you did?)  The .047 cap just before the volume pot, the 150pF cap on the top of the pot, to see if it's getting past the volume, and then the .01 at the input to the PI.

~Phil

[frankenxtein]

Looking at the schematic, I do think you s hould double check you have signal at several spots after the EF86.  (maybe you did?)  The .047 cap just before the volume pot, the 150pF cap on the top of the pot, to see if it's getting past the volume, and then the .01 at the input to the PI.

~Phil

Yeah I changed that cap (was good)  just to be sure The bass and treble controls I'm not sure about but the signal comes thru up to pin#2 on the PI. I must have it wrong assuming the schematic is correct. I should get something thru the phase inverter or does it take more than 5vac to get something out the other ends?

[pompeiisneaks]

Off the top of my head I don't recall what I've seen in other amps at the PI side, but I think 5v seems about right, if it exists at the volume pot and doesn't after it, maybe the volume pot is having issues? Basically you can use the sound sniffing thing you have to see where it disappears.  If it exists just outside the previous stage, after that .0047 coupling cap, and isn't there right before the input to the PI, that means it's lost in the volume area. 

~Phil

[frankenxtein]

I decided to rebuild the PI valve , neater. maybe I 'll get it working right.

[pompeiisneaks]

Well, if I understood what you said, though, the signal is lost right before the PI, that means to me the PI isn't the problem, If the PI was the problem, you'd lose the signal after the coupling cap before the power stage. 

~Phil

[frankenxtein]

Well, if I understood what you said, though, the signal is lost right before the PI, that means to me the PI isn't the problem, If the PI was the problem, you'd lose the signal after the coupling cap before the power stage. 

~Phil

The signal wouldn't go to the other side of the input cap @ the phase inverter. Basically the phase inverter is blocking the signal? It stopped at the cap. There well may be issues for sure in the controls back the other direction too.

I re flowed a few joints on it and then the thing went off balance. My solder job was not real good and after staring at it for two days. I cleaned up the socket and will have it together again soon maybe better lol.

[frankenxtein]

116VAC primary

V1 1&6 - 166.6v cathode 1.956v
V2 plate 108.4v , screen 89.7v , cathode 2.4v
V3 pin1 308.3v , pin6 296.3v , bias 78.8v
V4 plate 412v screen 405v cathode 29.2v
V5 "                               "cathode 29.3v

B+ A- 419v, B- 415v, C- 390v, D- 374v, E- 174v

Signal test
input jack 74.5mv in 5751 V1 out 233.5mv
ef86 79.2mv in 18.5v out
PI 3.79v in 3.4mv out

All that and  nothing lol.

 

[DummyLoad]

PI coupling caps attached to the wrong end of the plate load resistors?


--Pete

[frankenxtein]

I beginning to think this design is a bad joke to be played on noobs , like myself 

[pompeiisneaks]

I don't think the ac signal can be 'blocked' by the next stage, the next stage may just be doing nothing with it, but if it's not there post coupling cap, it's being lost prior to the PI.

~Phil

[frankenxtein]

Some high res photos of this mess

https://www.dropbox.com/s/lb1rd0o8c8kb9u8/IMGP0129.JPG?dl=0

https://www.dropbox.com/s/hsbywcpu7we0dx0/IMGP0130.JPG?dl=0

https://www.dropbox.com/s/b1sudpbdmi7e4u7/IMGP0131.JPG?dl=0

https://www.dropbox.com/s/7l29z6dh1arx3ka/IMGP0132.JPG?dl=0

https://www.dropbox.com/s/f0j822w17gvgg6p/IMGP0133.JPG?dl=0

https://www.dropbox.com/s/ka2lihhvammbcc5/IMGP0134.JPG?dl=0

https://www.dropbox.com/s/z24hx29nrewdpr8/IMGP0135.JPG?dl=0

https://www.dropbox.com/s/ocbxu73quhbs5ku/IMGP0136.JPG?dl=0

https://www.dropbox.com/s/pafumbk67i7gajt/IMGP0137.JPG?dl=0

https://www.dropbox.com/s/yx99nxwksb218ce/IMGP0138.JPG?dl=0

https://www.dropbox.com/s/g2piudwdcq5xtoe/IMGP0140.JPG?dl=0

https://www.dropbox.com/s/8xtxywh76cizdpb/IMGP0141.JPG?dl=0

[frankenxtein]

 Took a  Naproxen and prepared to troubleshoot the Mangler , after cleaning up the PI (got all the trash out too) Hooked up my cell phone with it's tone generator , getting ready to chase the signal. Flipped it on and noticed the cord I'm using to patch the phone in is really noisy 

5th times a charm on phase inverter. I'll try to document the AC signal voltages so as to show , what to look for if I can. To help someone else troubleshoot.

Now my problem could have been a bad socket too. I noticed I was able to push the backside of the sockets on the pins a little more than was catching. Maybe a 1/16th of an inch.

With the 16 ohm speaker just sitting face down on a piece of plywood , barely opened up , they'll hear ya .... this thing is loud and very quiet.

 Seems I've got the treble control reversed haven't fixed that yet? But it works!

[frankenxtein]

I beginning to think this design is a bad joke to be played on noobs , like myself 

Well that was dumb  Thank you friends

[frankenxtein]

primary 115vac
B+ A 412v , B 409v , C384v , D 368v , E 172v

V1 160v  cath 1.88v
V2 plate 108.4v scrn 86v cath 1.95v
V3 pin1 298v pin2 287 bias 73.5v
V4 plate 400v scrn 374v cath 25.68v plate 34.9ma - scrn 3.53ma = 31.37ma/ea
V5 see V4 very close
300ohm cathode resistors Started with 360ohm resistors pdis 24ma/ea
Added 1k 25w resistor on screen supply as per original schematic marked in red.