# Pepco Riviera: Rebuild or Strip



## TeleToons

Picked this amp head up this summer for cheap. It worked so so. There was no discernible difference between the two channels or the four inputs. It would hiss and pop a bit but I left it on the back burner while I built a 5F1 clone.

Today I was mucking around playing and I moved the guitar chord and the amp let out a loud hum, not the heater wire kind but a "not a good thing" kind. So I finally put it on the bench and took a look inside. The amp has been messed with a bit, one half of a cap can has been jury rigged to a bus bar, there's a cut wire coming off a tag strip that the OT is connected to etc. Still has a two prong ungrounded plug though.

Any how, this little beastie has what appears to be an El84 as a rectifier, along with two other El84's as power tubes and two 12ax7's in the preamp. Markings are rubbed off that tube but I think I read about the amp on this forum before. Question for me, since I have not heard what this amp actually sounded like back in it's day, and since there does not seem to be much info or any schematic for it I'm not sure what to do. And the El84 as a rectifier is a head scratcher for me, but that's not saying much.

Ideally, it would be nice to return it to original condition. But I am very much a newb at this and without a schematic to work from it's going to be tough to figure what exactly has been modded and why. So I am leaning towards taking down existing voltages and labelling the leads from the trannies. When I get that far I am thinking about pulling the amp apart and using the trannies to build something that fits their power ratings.

So there's the question. Was this amp ever desirable enough for it's tone when it was new to try to restore it, or is there more value in repurposing the trannies etc into a more common configuration ?

PS:
The cab is a bit rough, faceplate a bit marked, but it's no problem using it as is. If I gut the amp, I will probably be making a new faceplate or painting over the existing one.


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## dcole

I personally rebuilt my Pepco 725 to match the normal channel of a silver face Deluxe Reverb. It sounded beautiful once I did that. I don't know much about the model you have but I would rebuild it. These amps aren't something people are screaming for and for a good reason. They had non-standard circuits that didn't always sound good. When I bought mine, the guy was all proud to say you could push it as hard as you want with your guitar and it wouldn't break up. That wasn't because it was some monsterly powerful amp. That's because there was no gain in the pre-amp!


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## greco

This old thread has some content about the same amp you have (Riviera ER30)

http://www.guitarscanada.com/showthread.php?31359-so-ummm-more-impedance-questions

See post #25, etc.

This is a nice pic of the underside of the chassis...for comparison/reference.










Cheers

Dave


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## greco

This English WEM ER30 amp looks a bit similar...do you think?

http://www.vintagehofner.co.uk/britamps/watkins/er30/er301.html



















Cheers

Dave


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## mhammer

Not sure how I acquired this link. May have even been here. But the site details conversion of a Pepco 725 into something better: http://www.alerich.com/hifi/hotrod20/


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## TeleToons

Thanks for the replies. That shot of the underside is interesting. It proves the cap can attached to the bus bar is stock. Mine is half disconnected though. The pic of the English WEM is revealing. Mine has Made in England cap cans. That pic also shows what has been cut out of mine, the original speaker connection by looks of it.

I will be taking allyour advice and rebuilding into something a bit more familiar.

Thanks again

Rog

- - - Updated - - -

Oh and all that rust you see in the gut shot is actually some kind of crud that can be wiped off. I am guessing cigarette tar eeww


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## TeleToons

And after looking at the link that Greco posted, my Riviera seems to be the very same one that Frazer had in that post. Ha ha, small world


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## Lincoln

I can't see how an El84 could function as a rectifier. This amp must be a push/pull El84 with a solid state rectifier of some kind. See any thing that looks like diodes on the underside of the chassis?
My vote would be to re-wire your amp into something else. There are plenty of dual El84 amps to choose from.


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## epis

Lincoln said:


> I can't see how an El84 could function as a rectifier.


I was interested in it as well, so I have checked out first greco's link. They used it as half wave rectifier (all the grids are connected to the anode).

http://s281.photobucket.com/user/spliff-devine/media/gc/12A6_as_Rectifier-1.png.html


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## greco

Hopefully, "fraser" will see this thread. 

@TeleToons..Ironically, he lives in Hamilton also. Very small world indeed.

I'm following this thread with interest.

Cheers

Dave


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## dcole

I would check that WEM circuit out versus what Pepco did. The 725 amp I had looks like a Fender, but once I checked the circuit I noticed it was way off and it sounded horrible. You could rebuild it the same as WEM if its off at all or even rebuild it like the Watkins Dominator or Marshall 18 watt circuit.


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## epis

It looks to me very much as WEM ER15 . http://www.vintagehofner.co.uk/britamps/watkins/er15/er152.html

Only with "normal" full wave rectifier. http://www.vintagehofner.co.uk/britamps/watkins/schematics/er15.html


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## epis

I would definitely restore it toward WEM specs. Cheers, Damir

P.S.

another useful link : http://www.tonegeek.com/musicgear/amps/wem-control-er-15.php


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## TeleToons

Wow thanks for those links epis . Definitely gives me some ammunition for the old brain to work with. Got to wonder if the amps are identical or if the marketing for the Riviera went: two 15 watt channels = 30 watt amp


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## epis

You're welcome but you should thank dcole , WEM ER15 is equal to Riviera ER30 except rectifier and inputs, transformers and "intestines " look the same.
Good luck with your project !


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## TeleToons

Looked up the Dominator and the 18 Watt Marshal circuits as dcole suggested. Never knew the history of the Dominator before, interesting for sure. The WEM ER15 is marketed as a bass amp. Lots of options out there. A closer look at WEM and Pepco gut shots leads me to believe that Pepco, which is a Pine company branded name, copied the basic WEM layout. The WEM looks a lot more refined and of better craftsmanship unless of course my Pepco has been torn apart at various times.

It's so cruddy I will probably strip it. Maybe do it something like this. http://mhuss.com/18watt/schematics/18wattLite.gif but it looks like it is on the back burner.

Going to button it back up and shelve it. I have another one on the go atm on my bench. A simple "Savage Croaker" amp from the WATTKINS amp forum folks.

Thanks for the replies. A very warm welcome to a guy who just joined and made his first posts. :smile-new:


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## epis

Whatever you decided to do, if you need any help, just come back to forum, here is a lot of knowledgeable guys willing to help.
I do agree, 18watter is good choice for the transformers and mustard caps you have in that chassis. Cheers, Damir

P.S.
I would say your amp was made by same factory as WEM. I think it's just rebranded to Riviera.


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## fraser

yeah, this was my amp. i acquired it in the early 90's someplace-
i was using it as a bass amp, and sometimes a vocal amp.
sometimes i daisy chained it with other amps for guitar.
ran into money/life hassles, and ive got a pile of stuff, so i sold it a few months back.
i dont know much about it, but good luck and have fun to the op-


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## parkhead

epis said:


> Whatever you decided to do, if you need any help, just come back to forum, here is a lot of knowledgeable guys willing to help.
> I do agree, 18watter is good choice for the transformers and mustard caps you have in that chassis. Cheers, Damir
> 
> P.S.
> I would say your amp was made by same factory as WEM. I think it's just rebranded to Riviera.


I'd agree all english parts it was probably made by WEM for pine electronics 

low gain the first thing in the circuit is a 250k volume pot acting as the input grid ... most of the signal is being lost right there !
the rest looks like it could be a real screamer 


p


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## Church-Audio

I would ditch the el84 and put in a new socket for a 5y3 then rewire then instal a JJ 40x202020 in the amp put the 40 on the first node and the 20s on all the other nodes... I would need to see a schematic on this amp to figure it out. Or simply replace the caps clean it up and call it a day.


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## TeleToons

I made up a shopping list based on The Tube Store's stock and replacing the caps won't be all that expensive. I would do that and get it running right first I think. I do not have much experience at all but think I read that using a 40uf cap with a 5y3 will stress the 5y3? 

Lots of options with the trannies and tubes that are there, but I want to hear it stock first. Going to be a winter project at any rate.


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## keithb7

At the risk of reviving a zombie thread I thought I would contribute an update from a Pepco Riviera ER30 amp that is currently in my possession. 
I think it's worth recording my findings for future internet searches.
From the front, and looking at the guts, It looks exactly like the one in the photo at the beginning of this thread. 
I suspect the original author, was not sure about the tube rectifier as it does indeed look like an EL84 tube. However it
was indeed a rectifier tube.

Here are my bench notes:

It is full tube, including one full wave rectifier tube which is a 6CA4 tube. The main power tubes are both EL86 (6CW5) I suspect the total output power of the amp is about 5-6 watts. It sounds like it to my ears. I think it is a class A amp,
as I don't see a push/pull tube. A 6CA4 tube in a class A amp creates a power output of about 5.6 watts. This amp
has 2 6CA4 tubes, but I suspect there is one operating for each channel maybe? It does not seem loud enough for
two 6CA4 tubes to be working together. It seems like a unique circuit.


There are 2 pre-amp tubes, 1 for each channel I believe, both 12AX7. Again I suspect
1 12AX7 per channel, working with 1 EL86 power tube for a class A single ended amp.
I suspect there might be 2 mostly independent class A circuits functioning inside this amp.


It uses a single section multi cap can for the B+ circuit. It's made in England 50uf/50uf at 350V.


The one I have has a JJ brand 12AX7 in one side, and a "made in the UK" Sylvania 12AX7 in the other.
For kicks I tried swapping in some other brand vintage 12AX7 tubes I had, to see if I could get any different noticeable tones. 
The amps offers little to no break up. I pushed the input with a tube screamer style pedal, set to clean with the volume cranked, 
it got dirtier. Especially with some P90 PUs. I suspect humbuckers would offer more gain.

The amp here seems to function perfectly. It's quiet and plays well. The owner would like to get more gain out of it. Not having a schematic
to work with, I don't feel confident enough to modify it. It seems to me, that the amp was designed to stay clean, with 2 separate circuits, maybe to 
host 2 different instruments playing together through one amp?

Depending on the price paid for the amp, it may be worth gutting and putting in a 5F1 or a 5F2A circuit. They are certainly more known, popular
and deliver good amounts of gain. I think it might be worth it just buying a good transparent OD pedal to put in front. Maybe a Timmy would be
great here with this stock Pepco amp. Maybe I will suggest that to the owner. It actually sounds pretty good clean. Nice, full and some chime.

Pics below. - Keithb7


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## keithb7

Here are my photos. Let me know if you cannot view these. I struggle sometimes with sharing photos from my Google Drive.

Edited photos again. Try this?


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## greco

Can't see the pics. (using Chrome)


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## keithb7

greco said:


> Can't see the pics. (using Chrome)


How about now?


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## greco

Perfect! ..Now I will take some time to look at all your work. 

Cheers

Dave


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## epis

Hi Keith, I suggest you to read previous posts in this thread. Your amp is the same as WEM ER15. I can bet 6CW5s aren't original.
(they are rated for 170V, but pin compatible with original EL84 - 6BQ5 ) 
Amp is push-pull, but there is no dedicated tube for phase inverter. Each channel preamp tube 12ax7 is 1/2 preamp, 1/2 part of PI.
You can't use it's parts to build Champ, but, it could be great for 18W Marshall. Cheers, Damir


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## jb welder

If you bridge the 2 channels and play around with both volumes does that do anything for the gain?


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## Lincoln

anybody notice that mustard cap with the big boil on it's face in picture 2 & 3? That doesn't look good


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## keithb7

epis said:


> Hi Keith, I suggest you to read previous posts in this thread. Your amp is the same as WEM ER15. I can bet 6CW5s aren't original.
> (they are rated for 170V, but pin compatible with original EL84 - 6BQ5 )
> Amp is push-pull, but there is no dedicated tube for phase inverter. Each channel preamp tube 12ax7 is 1/2 preamp, 1/2 part of PI.
> You can't use it's parts to build Champ, but, it could be great for 18W Marshall. Cheers, Damir


You make some good points Damir. Yes there is a very good chance the amp was modded from the original design.
If the one I have was indeed push pull, would it not be a lot louder than other 5W amps I own? It is not. It sounds to me, 
like the output of about a 5W amo. I also have 12W, and 18W amps. It's nowhere near the volume of those when plugged into the same speaker cab.

Plugging one channel into the other seems to make no difference to the amount of gain it gives up.
It would appear tho that my version is indeed modified.

- - - Updated - - -

Yes I saw that blister on the mustard cap too when I had it apart. It seems to be some sort of waxy coating. Like it was sprayed on too heavy and dripped.


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## epis

Well, If you have checked out the schematic diagram, you may see only one triode stage in the preamp. (per channel) It can't give enough push to PI and output stage as "normal" guitar preamp. Even Champ has two triode stages in the preamp. Other reason is tubes difference. For example single EL 86 is looking for 2k4 transformer impedance where EL 84 needs 5K for max transfer of energy. So, if your output transformer is made for EL 84, you will experience the power loss caused by impedance mismatch. 
But main reason why is simply not enough signal gain in the preamp.


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## Church-Audio

You need to do a cap job on that amp the main filter is bubbled and ruptured and the cathode caps should also be replaced the mustard with the boil looks strange to me as well because it could be wax but there is no wax inside your amp.


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## traynor

These are awesome amps stock, don't let people convince you it needs changing. I own two of these amps. They are unique, hard to find in amps today. I have 20 amps in my jam room right now from Trainwrecks(3), Sound City , DR Z, Deluxes, Vibrolux, Reverberocket, Traynors, Bernie, ETC..and the ER15 is my go to amp, it loves all guitars.
I do repairs for music stores and I do Custom builds and as Chris Church says you need to do a complete cap job, and you need to go back to EL84 and also you need to make sure your output transformer is wired correctly. One of my amps came with the output transformer wired from the 8 ohm tap to the 16 ohm tap and not to common. The coupling caps C2-C15 are prone to leaking at least mine were bad, I'm talking about the WIMA can ones that go through the chassis. 
The input jacks are wired for attenuated signal like input 2 on a fender, to get the high input you need to stick a jack in the unused input. Also make sure the 4.7K resistors on the output transformer are good. Chances are the amp won't match the schematic exactly. Mine came with 220K plate loads on the first triode stage as an example, and a few other differences in values as well.
For my last words....Don't gut it, just because it's different does not make it a bad design. Study it and you will see. Please save us all from another Marshall 18 Watt, that bandwagon can't support anymore.


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## TeleToons

This latest discussion gave me a start! But I see the amp ended up as a push pull, maybe unique amp, once again. Mine is still untouched from when I posted originally. Still gaining experience and do not want to mess the amp up. Am building a 6G2 Princeton atm. When done I might take a look at the Riviera or maybe break down and take it over to Chris for an appraisal.

Traynor has convinced me to retain the amp as a Riviera and not cannibalize it.


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## keithb7

Thanks for your input folks. I did not see that bubble on the bottom of the main filter cap, thanks for pointing it out. I will see if I can find the replacement parts.


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## Church-Audio

keithb7 said:


> Thanks for your input folks. I did not see that bubble on the bottom of the main filter cap, thanks for pointing it out. I will see if I can find the replacement parts.


 the cap if it's 50/50 uf is easy to find. The tube store has them in Hamilton. They are cheap spend a few more bucks and get the f&t caps. You might have to change that clamp out. Because the f&t caps are smaller. You can use black tape but that's cheeses better to get the right clamp. It's clamp number 1 at the tube store.


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## TeleToons

So hi folks. Thread resurrecting time !

Finally pulled the Pepco Riviera off the shelf and gave it a going over. Am working off the Wem Control 15 schematic, almost identical.

Rectifier is an EZ81. Tubes are EL84's. Replaced the filter cap can and the 16Uf filter cap. Rebuilt the conjuctive filter on the OT. Half of it was missing. Replaced a missing resistor on one of channel 2's inputs. Couple of other electrolytic's and it's up and running. Both channels working and very quiet as far as hum. Does have the old "ground noise" that goes away when you touch the strings. That's with my single coil Tele. It's not bad though.

Not a whole lot of volume. My Champ is way louder. Just reread this thread and followed traynor's suggestion to stick a jack into the unused input. That helped quite a bit, although it is rather odd. Amp is still on bench and is plugged into an 8 inch Rola 8 ohm. Will try it out later with my 12 inch Type A Celestion and vintage Jenson P12Q. The Wem schematic calls for a 15 ohm speaker load. I do not know what this should be plugged into. There are three taps, one is ground, the center tap is wired near the outer edge of the OT, and the third tap is wired deeper near the center of the OT and is the one that is connected to speaker jack. I am thinking that's the 8ohm and the center tap is the 16, as it would have more wraps leading up to it ?

Pretty brilliant chime with the test speaker. Not much bottom end. Not sure yet as how influential the tone controls are. Do not seem to make much impact right now. None of the tone caps have been replaced and I can imagine they are not up to snuff.

Probably going to try a 500K or 1 Meg volume pot at some time as suggested above. And the second channel begs to be played with, but time will tell.


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## flyswatter

I have a 50-watt Pepco 725 head, branded Mansfield but much like the Rivieras. Because mine was based on a BF Bassman, I was able to cobble off of a Fender A864 schematic to completely restore it.

My amp when I got it was in about as bad condition as the OP describes, but if you know how to mod things they are well worth taking the time to restore. Changing the usual crapped out stuff like pots, switches, fuse holder, power cord, jacks, and maybe tube sockets (the ones in mine were loose and cracked) is half the battle. The electrolytics are another weak point on older amps.


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## traynor

Glad to hear you are working on the riviera. As i stated before make sure you are hooking up the output taps correctly. On my amp when looking from the back the left is 16 ohm middle 8 ohm and the right is ground. 
16 = 10K =.8 ohms
8 = 9.2K =.6 ohms
16 tap to 8 tap =.3 ohms
From your picture the black is 16 and the red is ground.

You mention not much low end, I'm surprised, did your amp come with .1 coupling caps off the first plate and (220K/2.2K). I like to leave one ch that way for my Strat type guits and change the second ch to .05 or .02 (100K/1.5K or 2.2K) for other guitars.
The coupling caps to the phase inv are .0047 It is odd to see it set up this way,but I love the sound. If you want you could try raising one ch to .01 or .02 and see if this helps with he low end. But I'm still surprised you feel there is no low end. I just realized you said 8" ROLA no wonder.......

Make sure you check all the values of your resistors and change the coupling caps after the first stage they all leaked in my amps. (the ones that go through the chassis usually WIMA brand). The mustard caps should be fine I've only found one that leaked in all my 16 years of working on amps.
I usually rewire the input grid leaks and stoppers for HIGH and Low just like fender. (I've never felt the need to wire it like the schematic). This gets away from having to insert a jack in the other input. Although I never use the HIGH input, too much gain too early.

You mention not much volume, Your champ is louder well something is wrong, yes the amp is not very loud, but louder than a champ. Post some voltages if you want, I have all of mine for each amp written down.
B= 324V
Plate =322V
cath =10.4V
Diss =10.7W
I don't mind the sound with the tubes only dissipating 10.6W besides the cab is not vented very well, although I have a fan mounted in each amp to help.
As for the grounding issue when you touch your strings, is that with the amp in the cab or on the bench. I don't have that issue but I do with other amps from time to time.
If you need more help with the amp just come by for a visit.
Brent


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## TeleToons

Some excellent advice there Brent. Thanks a bunch. I have only done the obvious repairs so far. 

Hmmm, I have not touched the speaker hookup on the OT yet, just repaired the filter. There is a black wire going to ground under that black speaker lead. So the OT is incorrectly wired. If the tap under the red lead is actually the ground and visa versa.

The four input jacks are all very worn, the guitar cord is pretty loose in the jacks. There is a 65k resistor from the #1 tab on the volume to the tip on the input, and there looks like a 1.6Meg on the input from tip to ground. That's just going by color code which is dirty and faded. Have to head out, will keep the thread updated as I go along.

Rog


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## cboutilier

My Riviera 730 is probably my favorite amp. It has wonderful cleans, a nice overdrive character, deep trem, and way more reverb than you could ever need. I used it for my last two studio sessions. 

I'm going to build a 1x15 combo cabinet for it soon, because the half stack is a pain to drag around to gigs. Otherwise, I consider it to be a pretty good facimile of a Deluxe Reverb.


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## TeleToons

Hey Brent, what schematic do you work off of ? Is it a Wem or do you have a Pepco Riviera one ? 

Back to the OT, if the 16 ohm tap is sent to ground, and the ground tap is sent to the tip, the OT would not work at all would it ? Wondering if mine is different than yours. There is a picture of a Wem OT that looks wired like mine. Black and red are same any how.


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## traynor

Sure it would, you can connect either end of the transformer to the speaker jack. It matters only when there is more than one tap. Looking from the rear it's 16 -8 - ground. use your meter it will confirm the values i gave they will be close. I'm using the Wem ER 15 schematic. To wire the inputs for hi and lo it's simple, just remove the ground wire on the bottom jack that goes to the tip (Shorting side) and connect a jumper from tip to tip of each jack. I can give more instructions or diagram if needed.
The picture you provided is from an original ER 15, and from the looks of it that Ch was modified for Vol and Tone, like a Marsh 18 Watt.


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## TeleToons

Have a 2 x 8 cab with '63 Jenson ceramics in it, wired for 16 ohm. Amp is sounding much much better, that missing bottom end is back too, and way louder. Was going to try it in my 1 x 12 8 ohm with the Celestion Type A so I could safely crank it to see if it overdrives. But played the 16 ohm cab for a few minutes and then the amp died with a sputter, tubes were all still lit so I moved over to the channel two. It was fine for a minute then it too died with a sputter. 

Let it cool down for a few minutes and it worked again so something is failing as it warms up. Tubes are all old stock organ pulls other than the rectifier which came with the amp. Will replace the usual suspect caps and probably the plate resistors. Not sure yet what to do with that second channel since I will be replacing components. And will most likely bolt a bracket to the chassis to mount two output jacks, and hook up both the 16 and 8 ohm taps. Right now the output jack is connected to the removable backing panel so it flops around on its leads while on the bench.

So I have some work to do. Grandchild number 4 was born yesterday so its pretty busy around here for the next few days. Will post results later in the week. But am interested in what you folks think might be failing.

Rog

Edit: And thanks for the input Brent. My ohm meter read 0.9 ohm and 0.7ohms verifying you are correct about the leads. I also have 0.3 ohms between the 8 and 16 taps.


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## jb welder

If there are only 8 and 16 ohm taps, then 8 will be the half way point of the winding. Either end of the winding could be ground and the far end will be the 16 ohm output.
It will work either way (8 ohm tap would be the same either way), however, if there is a NFB loop the phasing would be reversed. So if there is NFB and the OT secondary is wired up backwards, you would likely get instability or even loud feedback.


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## TeleToons

Thanks JB. Confident about the taps now.


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## traynor

Probably output tube issues. Make sure the pins on the tubes are clean and the sockets. Put your meter in the cut and watch it as it warms up. Do you have a light bulb limiter, you should make one if you don't.


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## TeleToons

Yes I use a light bulb limiter and everything is fine. But it was not connected when the amp fizzled out. Both power tubes voltages look good, Pins 3 = 11.o, pins 7 = 329 and 328, pins 9 = 309, but they are old tubes. Voltages are off for the 12ax7's. Think one of the plate resistors has drifted. Power tube pins were corroded so I buffed with 800 grit and cleaned with deoxit. Pins are slightly bent too. Will have to hook the meter up and try playing it again while watching the voltages.

Via pin1=177volts V2a pin1=196volts
pin2=68v pin2=68v
pin3=71 pin3=71
V1b pin6=137v V2b pin6=155 and faint radio staion signal
pin7 static pin7 static and loud radio station signal
pin8=1.2v pin8=1.08v

EZ81 pin1=296
pin3=297
pn7=333


Amp is about 10 volts over the schematic at the power nodes. I have 331v compared to 320 at first node, 307 compared to 300 at second and 262 compared to 250 at third.

Going to pop into the Tubestore, just across town for me and get some caps. I'll leave the mustards for now but I have no problem with changing them out too. And I have a pair of EL84's sitting in my AO35 conversion I can try out.


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## TeleToons

Swapped out the tubes. That wasn't the issue. I was going to mod channel 1 to a crunchier state, but because of the issues I just rebuilt it stock like channel 2. Gave it a test and it is behaving better. Tested with old tubes, was advised by the TubeStore to bias the output a bit cooler before I stick in my new Mullard EL84's so they can wait a bit for my next digikey order. The Wem schematic has a shared output cathode resistor of 130 ohm, this one has individual cathode bias resistors of 270 ohm, I worked out 107% bias with an online calculator. And 12.5 watts. Think I will drop it down with 300ohm 5 watt resistors and see how it sounds.

Still have to hook up an 8ohm tap and mount the output jacks to some kind of bracket. And right now there is no discernible difference between channel 1 and 2. I was down at Neutrics today and picked up 4 cliff style jacks and I think I will replace the old ones, and make a high low Fender type input.

And here's a pic of the top side just for fun


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## jb welder

Did you figure out why it was cutting out?


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## TeleToons

After swapping the tubes to no effect, I monitored the output tubes plate voltages as it broke down. They seemed stable so I assumed the power supply was ok. Channel two had been rebuilt with all new caps. Channel 1 was still stock. Because I was getting a fair imbalance in the voltages for the PI triodes and the pre amp triodes, I figured the caps and or resistors were failing. And the radio interference was on the channel 1 pre amp . So after changing them things seem ok but I really need to play it for an hour to make sure. And to honestly answer your question, no, I don't know for sure. The resistors were not that far off, who knows which individual caps were bad.

If it acts up I will continue the saga here. Maybe I'll get a clip of it playing once it's all back together for good. Eventually I am going to rearrange one of the channels. Seems redundant to have two of them the same like that.


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## traynor

You don't need to change the cathode resistors if they are close to 270 ohm that's fine, your only dissipating 10 to 11 watts per tube, my amps have the same voltages as yours. You can bias cathode biased amps at 100%.


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