Amp Head for DIY-Head

[Dr ZEE]

I've done some investigation. Preamp looks like 12AT7 and 12AX7, two 6V6's out. As soon as I turned it on I can hear a lot of 60 hz hum. Looking inside, I found that the tone arm electronics plug into the amp on a single RCA. I cobbled together a 1/4" to RCA and plugged in a guitar. If I can get rid of the hum, this will be a kick ass amp just as it is.

Sounds cool! Then you are all set, sort of
Now about hum. I really can't clearly point out how to deal with it for sure 'step-by-step'. If I'm not mistaken, some hum may be sort of normal, but it should not be terribly unacceptable.
My experience. When I turned on that last webcor machine it was totally unacceptable. Not just hum, but all sorts of ugly sounds. So, in my case it was the load of problems , I suppose. Since I was planing on complete re-design anyway, I've decided to replace all electrolytic caps, all coupling caps and all cathode resistors bypassing caps.
To give you a general idea, I've made THIS CHART - CLICK TO VIEW (better see one time than hear many times )
I would say you need at least to replace power supply filter electrolytic multisection capacitor. Would it be enough or would it be just what needs to be done in your case - I can't tell.
If you are going to try fixing it, again, be careful and follow safety measures.

I've ordered capacitors from W J O E RADIO - click to go to the page
I've found that man via e-bay actually, have contacted the seller and he said that he has various components for sale. I can recommend. Got my caps fast, the price is just fine from what I've seen around. Also, you can e-mail contact him with specific question about your unit and maybe get an advice.
OK, what else can I say. Fixing an amp like that is not very hard (assuming you've got bassic knowledge, ok soldering skills and you can discipline yourself while working (these are not toys )), but still , messy, takes time and all that. Good luck if you do. Post an update.
********
LINKS:
Here's a well put page about draining electrolytic caps: How To Drain Filter Caps (Fender DeVille/Deluxe example)

Tube Amp Overhaul (capacitors)

Replacing Passive Components to Improve Sound Quality (by Paul J. Stamler)

 

[arjoll]

If you're doing any work on vintage valve/tube electronics there is a heap of information at http://www.vintage-radio.com.

 

[Track Rat]

I have the amp module out of the box now and can see the caps/resisters and such. The multi output cap is paper and looks swollen. All the caps look OLD. Still, it looks like a cool project. At least the schematic was glued to an inside panel.

 

[thebrontosaurus]

Here's Webcor Regent Stereofonic (2323) r-t-r machine to Guitar Amp Head Project in details

i dont suppose someone with limited electronic knowledge and a similar webcor deck could create a head out of it.... maybe?

but i looked through your site and i was thrilled
absoloutly in awe!

great work on everything youve done,
id love to get onto some projects myself.

may i ask how you got into all of this?
because im very interested!

thanks,
noah

 

[Dr ZEE]

i dont suppose someone with limited electronic knowledge and a similar webcor deck could create a head out of it.... maybe?
...id love to get onto some projects myself.

someone with limited electronic knowledge - that would be me. so ...
start with something that you feel comfortable based on your skills and knowledge. I don't really know how else to put it.

... i looked through your site and i was thrilled
absoloutly in awe!
great work on everything youve done,

cool! Thanks!

may i ask how you got into all of this?

I'm not sure what do you mean by "getting into all of this" . In my case it's just a part-time hobby, part-time of a bigger hobby - music writing/playing/recording/producing, that is. That bigger hobby has gotten out of control, I must add
********
Which 'similar webcor deck' you've got? Model?
**********
Just one more time - NOTE.
If you really are very beginner in electronics, then I'd advise you to start with some low voltage projects. I don't know, hmmmmmmmmm, maybe get some basic electronic projects kit(s) and make something up while practicing and learning basics. (Here's link - http://www.electronickits.com/kit/complete/complete.htm)
If you are pass the basic skills, then get some basic knowledge about vacuum tubes, learn safety measures.
When you feel comfortable - get some simple amp - fix it or something.
One thing to keep in mind is: when working with high voltage electronics you can't (better not!) do something in a style ala: "I have no idea what I am doing, but let's see what happens if I just do this". It is not a good idea. No jokes here. Also you have to be able to discipline yourself, even when you know what you are doing and why you are doing it.
*******
Now, in respect to crafting, woodworking, designing and all that sort of stuff - that's just what your hands can do. The more you do it the better you at what ever you do. Crafting that is.

good luck and all that

 

[Dr ZEE]

The multi output cap is paper and looks swollen.

I'd say it has to go. Also that maybe the only thing you'd need to 'fix'. If there are some sausage-like looking caps in there, you can also may replace them, but they maybe just fine. If you can't check them, then just replace them. Well, the amp may loos some its "character", but that's depends on who's listening, really.

At least the schematic was glued to an inside panel.

That's what I'm talking about! Good things used to come with schematics diagrams. Nowdays things come with list of trademarked titles .
Also, don't try to take it off. It ain't gonna come off, That glue is tough...and paper is paper plus it's old.

/respects

 

[Track Rat]

I hear you my friend. I'm going to start with replacing that to start with and go from there. The hum is obnoxious but the guitar through it sounds killer. I can't get over how crunchy and how much sustain it gives.

 

[thebrontosaurus]

********
Which 'similar webcor deck' you've got? Model?
**********

ill get back to you on that.. its at home. the play motor no longer works so i have no problem discarding that at least.

Just one more time - NOTE.
If you really are very beginner in electronics, then I'd advise you to start with some low voltage projects. I don't know, hmmmmmmmmm, maybe get some basic electronic projects kit(s) and make something up while practicing and learning basics. (Here's link - http://www.electronickits.com/kit/complete/complete.htm)
If you are pass the basic skills, then get some basic knowledge about vacuum tubes, learn safety measures.
When you feel comfortable - get some simple amp - fix it or something.
One thing to keep in mind is: when working with high voltage electronics you can't (better not!) do something in a style ala: "I have no idea what I am doing, but let's see what happens if I just do this". It is not a good idea. No jokes here. Also you have to be able to discipline yourself, even when you know what you are doing and why you are doing it.
*******

-true! I read some chapters and what i have worked on is usually battery powered. I got excited about making a head, especially since i have no where near the money to buy one, and i have to use a powered mixer.

Now, in respect to crafting, woodworking, designing and all that sort of stuff - that's just what your hands can do. The more you do it the better you at what ever you do. Crafting that is.

i built some speaker cabinets over the summer for some columns that had seen their day. woodworking is the part that comes much easier for me.

good luck and all that

thank you!

I think I will order some of these projects. Ive been through catalogs but never thought to actually order them.

I have a Craig Anderton book, "Electronic Projects for Musicians," that i found in a heap of books at an antiques shop. (the same place I picked up the webcor for fifteen bucks!). however helpful the introduction was i never was able to gather all the parts for a whole project. It may have been that this book was last published in 1980.

anyway, thank you very much for your response,
and keep in touch!
I would love to know the advancements on that ampex reel.

..she looks gorgeous.
-noah

 

[Dr ZEE]

I would love to know the advancements on that ampex reel.

No 'advancements' as the recorder itself, another words its original electronics were not modified in any way. (It was just generally serviced (mostly mechanical parts), bad play-back head was replaced, fixed cooling fan, added power cord with chassis ground.)
It was adapted to be more conveniently used as two channel mic preamp (so the motor on/off switch was added to silence all the mechanics) and as tape-delay effect unit (as demonstrated HERE). For that purpose the Front IN/OUTs panel and VU-meter/Preamp unit (which is independent of the recorder itself) were designed.
The project details are [here].
********
p.s.
Bookmark ESP-Pages, some good info/thoughts/andBlah-Blah is there for DIYers.

/respects

 

[Dr ZEE]

Mike (TR), I've updated Replacing Capacitors Chart. I've added (on the bottom) demontration how to use the "base cut" of the original multi-section capacitor to mount new caps on top side of the chassis and so you can keep all the original connections of components and leads on the bottom side of the chassis. Also depending on the situation you are dealing with, but it may be somewhat easier way, than adding terminal strip(s) on the bottom etc. I am going to use this "method" when I get to replacing caps on the earlier webcor amp I've built, which works ok with all old caps but is kind of noisy, so I am thinking about some more work on it.
/later,
/respects

 

[cjacek]

That is IMMENSELY cool! I'm speechless ... Thanks for that Doc!

 

[Beck]

Very nice work, ZEE.

Hey... give the good doctor some rep!

Tim

 

[cjacek]

Can't do it from my end ...

 

[Track Rat]

We'll my good Doctor, it's been like pulling teeth but I finally located a local parts place with some 400V 47u caps to replace the exploded multi tap cap. It was 25, 20, 20 and 15 uF so I picked up 8 of these and have an arry that translates to one 47u, two 23u and one 15u for the power supply filter section. Mounting WILL be the challenge here as the chassis is quite small (solid copper!!).

 

[Dr ZEE]

Mike, that sounds like you'd have to mount couple of strips. well, good luck there. drop a note how's'goin'
********
Tim, Daniel and, I guess..., Dave? Thanks a ton, guys!
The more reel-to-reel machines I destroy - the more green I get ..heh heh heh
here's visual ("rum IS in the basement")

 

[Track Rat]

Well Doc, IT'S ALIVE!!!!!!!!!!!!!!!!!! I replaced the caps and put everything in a 2U rack mount kit box and it screams. I love it.

 

[dragonworks]

another good use for dry ice.
Take a 2 liter plastic soda bottle
fill about halfway with dry ice
ad water
put cap on shake vigorously
throw and wait
KABOOM.

 

[Dr ZEE]

... it screams. I love it.

CoooooooooooooL!
now what? heh heh ...
I'm gettin' into spring reverb area. Got some no so live not so dead "bodies" on the table. It's getting colder outside. Slows me down.
/respects

 

[Track Rat]

I'm looking HARD into some tremolo stuff. I'm on a new mission. BUILD MORE AMPS!

 

[Dr ZEE]

heh heh, new mission ... this stuff may become addictive.
btw, I am getting often some mystery tremolo like effect here and there with tube amps, which are sort of not under control and I have no clue why it happens. I kind of like that "mind on its own" behavior of a gear, that makes life more interesting , sort of
try to play bass through it too... just gently, you know. also experimenting with using different speakers if fun.