1950's Ampeg Amplifier

[KingCameron]

I have recently purchased and hope to retore this 1950's Ampeg. The only problem is, I don't know exactly what it is, and could use a schematic.

This amp has:
1 - 12 inch speaker

Pre-amp:
2- 6SL7
2- 6SJ7

Power-amp
1 - 5Y3
2 - 6V6
2 - 6SN7

The control Panel
Small- Ultra High
Intensity
Speed
Vol 1
Vol 2
Treble
Bass

[Dave Curtis, dB AudioTech]

got pics?

[KingCameron]

1950's Ampeg

Here are some pics

[Dave Curtis, dB AudioTech]

Contact Rich Koerner:

http://www.timeelect.com/

He knows old Ampegs better than I do.

HTH,
-Dave

[KingCameron]

Ampeg Resto

Thanks Dave,
I bookmarked the page and will contact Rich.

Regards,
Cameron

[Tom Phillips]

I believe that you have a 600 series or a 700 series amp.
Ampeg used the power amp section in several different models. The Pre-amp (Top) chassis was changed to define the model of the amp. There were lots of variations making it difficult to find an exact schematic.

Regards,
Tom

[KingCameron]

600 0r 700 series

Thanks Tom,
I had reached near the same conclusion, as you stated. I am hoping I can find out a method to identify which one of 600/700 series it was.

After I can identify it, I will set about finding a schematic. I usually build my own layout diagrams, as many componets changed inside the same series during these years.

Cool amps like these must be returned to life!

Thanks,
Cameron

[Enzo]

May I suggest looking at schematics as a way to identify the amp rather than the other way around. Look up any you can find of the era.

[teemuk]

600 or 700 Series?

By the way, does anyone know a good link for these old Ampeg schematics? From searching through the usual (Schematic Heaven, The Unofficial Ampeg Page "Bluemuse", Dr. Tube, Free Information Society and TDSL - even the Aspen Pittman's schematic CD) the only thing I could find was a schematic for the model 625D. No other references to 600 - 700 series whatsoever. Do computer scans of these circuits even exist?

[Tom Phillips]

By the way, does anyone know a good link for these old Ampeg schematics? From searching through the usual (Schematic Heaven, The Unofficial Ampeg Page "Bluemuse", Dr. Tube, Free Information Society and TDSL - even the Aspen Pittman's schematic CD) the only thing I could find was a schematic for the model 625D. No other references to 600 - 700 series whatsoever. Do computer scans of these circuits even exist?

I was surprised to come up empty haded too. It's a shame that there is not more technical information such as schematics in the book "Ampeg - The Story Behind The Sound" by Gregg Hopkins & Bill Moore. The book is an excellent read which I recommend for those interested in Ampeg history and facts..

Cameron - Your photo shows that the pre-amp section appears to be in original condition with the exception of the tubes. However, I don't remember seeing bathtub caps used like that one in the upper right corner.
You will be able to make a schematic using existing available drawings as a guide if you don't find an original schematic. If you do find an Ampeg schematic, there will most likely be differences between it and your exact amp.

The 600 series were guitar amps and the 700 series were accordion amps. You may be able to identify your model by slight differences in the pre-amp component values using other old Ampeg schematics as a guide. That is, if it really matters to you. The real goal is to have an amp sound that you like.

Good Luck,
Tom

[KingCameron]

1950's Ampeg Identification

Great Guys!
Thanks for the info!!

By the way.. Where did Teemuk find the 625 schematic?

Any future help on this would be great too!!

This amp is quite interesting as it appears to be two seperate amps in the pre-amp, fed to one power stage. I am wondering if this is the "Duette"?
There are two Octal type connection cables running down either side of the amp, that appear to connect either side of the pre-amp.

Anyway, I'll keep digging on this.

Thanks again for your help!!

[Tom Phillips]

?it appears to be two seperate amps in the pre-amp, fed to one power stage. I am wondering if this is the "Duette"?.

It?s possible that you have a 1957 Model 6020 Zephyr Duette. What are the date codes on those brown paper covered Astron electrolytic caps?

There are two Octal type connection cables running down either side of the amp, that appear to connect either side of the pre-amp.

The normal arrangement would be for the cable on the right side, as viewed from the back, to carry the AC power to the lower chassis and the AC heater supply back up to the pre-amp chassis. The left side cables will be the signal from the pre-amp to the phase inverter. Note the RCA phono connector near the center of the power amp chassis. The left side plug probably carries the DC supply voltage up to the pre-amp too.
[Input invited if anyone knows different]

By the way, your photos have really helped support this discussion. Good job.
Too bad the back panels are missing. There might have been a schematic glued inside one of them. I wonder if there is anything glued on the bottom under the power amp? This is highly unlikely but have you looked under there yet?

Regards,
Tom

[Tom Phillips]

Cameron,
Check out the following link.
http://www.ggjaguar.com/duette.htm
Looks like your amp is NOT a 1957 Model 6020 Zephyr Duette.
But we are getting close.
Tom

[teemuk]

By the way.. Where did Teemuk find the 625 schematic?

http://www.schematicheaven.com/ampegamps/ampeg_625d.pdf

[KingCameron]

1950's Ampeg (Not a Duette 6020)

Tom,
You are right. It is NOT exactly this amp, but somewhat close.
I think we are on the right track here.

Some box demesions, same control panel, slightly different tube configuration and speaker complement.

I have been told that the speaker that is in this amp is the "Old Water Pipe" series. Meaning that the speaker magnet was made from a peice of water pipe.

Regards,
Cameron