Tube Amp Archive

I'm working on a design for a stereo combo amp, more than likely 2x10 or 2x8. It will have a builtin mono-in/stereo out digital delay and reverb module.

Obviously there's only so much separation you can get with an open back cab and two speakers sitting right next to each other.

I've never seen the inside of a Magnatone. Did they have any kind of baffle separating the speakers?

I'm wondering if something similar to the Watkins Dominator cab might help with separation.

I'm not overly concerned with perfect separation. If you've ever heard the chorus on a JC 120, you know it doesn't have to perfect to get a bigger and more animated tone.

An open back cab affects the low frequencies more than (if at all ) the high frequencies. Since just about every stereo these days has one subwoofer instead of two, I would think an open back cab wouldn't be an issue.

LeftyStrat wrote:I've never seen the inside of a Magnatone. Did they have any kind of baffle separating the speakers?

No, and now you have: http://www.vintageguitar.com/11040/budd ... atone-280/

Holy crap!
Man that would be some amp to own.

I can't imagine what it's worth.

Swart seems to have done a real sweet job with their stereo rig. It's not a combo but it sure does sound cool. I'd like to have a look inside the speaker cab they have. They say that baffles are nearly at 45 degree angles. That makes way more sense to me than both speakers pointing straight at you. I know with my stereo setup just angling the speaker cabs by 10 degrees gives a much better separation between right and left.

This thread gives me the chance to show off my Capitol amp, yes it's stereo. Four 7591 tubes with cathode bias. Built by Lectrolab in 1961. I've never seen another one like it. To get increased separation, there are extension jacks in the power amp chassis for each channel.

[IMG1200]http://i55.tinypic.com/2z4emis.jpg[/img]
[IMG1200]http://i52.tinypic.com/2626po7.jpg[/img]
[IMG:640:480]http://i54.tinypic.com/1zee04h.jpg[/img]

Very cool! What all does she do?

Reeltarded wrote:Very cool! What all does she do?

The function switch allows you to select one output transformer and speaker for half power, or two OTs and speakers for full power. When the function switch is set to stereo, the A channel guitar input goes to one speaker, and the B channel input goes to the other speaker. Set the function to AB, and the inputs from channels A and B are mixed together and go out to both speakers. Set the function switch to A, and the A channel input goes to both speakers for full power. Set the function switch to B, and the B channel input goes to both speakers for full power. It has a good sounding tube tremolo with controls for speed and depth. There's a single volume and tone control for each channel. Each channel has a bright switch. The speakers are original Jensen C12Rs. It has six 6EU7 tubes, and a GZ34 rectifier. It has a cathodyne phase inverter for each channel. The amp should make 28 watts per channel, according to Sylvania tube data sheets - 450 volts on the plates for a pair of 7591s in cathode bias. The amp has a nice early breakup, and a lot of compression. I've got my eye on a used Gibson Lucille guitar (stereo 355), if I can get it for a reasonable price. That way, I can really use the stereo capability of the amp.

Nice amp indeed.

Milkman just built a stereo amp. This must be catchy I better not watch this thread anymore.

Nice!

How about a stereo pedal, like reverb or delay?

Or a Maggie. Perfect rig to add a Maggie.

Reeltarded wrote:Or a Maggie. Perfect rig to add a Maggie.

I checked out the Maggie on youtube, and I really wanted to like it, but I just didn't like the sound of it. It sounded authentic, but that's not a guitar tone I really need.

M Fowler wrote:Nice amp indeed.

Milkman just built a stereo amp. This must be catchy I better not watch this thread anymore.

yes and after about a million emails back and forth with Peter Mather we decided it will not work in a combo unless I make it huge.

I ended up with a split setup for the stereo Milkman. If you want to hear mine, put headphones on and click here:

http://milkmansound.com/news/sneak-peek ... -amplifier

I am building another one with stereo cabinet that Mather and I worked on. Its not too different than the Swart stereo cabinet except its got 2 Jupiter 10's and looks a bit more Fender-like