Ampeg Echo Twin

[dragonworks]

Picked up a basket case Ampeg Echo Twin.  Missing one output transformer and a bunch of stuff. This will keep me occupied till I die and it will never be fixed. Luckily I didn't pay much for it. I love Ampeg amps and just couldn't help myself. I can always use the cabinet, still has the original speakers, I haven't tried them to see if they work. The gent I bought it from says the one channel still works, but from the looks of it I highly doubt it. Had it over a year now. One of these days I might just plug it in and burn the house down. It was cheap enough where I didn't even bother checking it out, we met in a parking lot and I took it and ran.Thanx for the shoulder to cry on.J.D.

[Williamblake]

You have an output trasformer a speaker and a cabinet and a power supply. Get a light bulb limiter and knock yourself off?

[dragonworks]

Two Jensen speakers. It is a stereo amp, so, one channel might work? I have a variax, one of these days Alice.

[shooter]

I brought one back to life, the small chassis, the amount of SH T cramped inside is not for the faint of heart.
was a fun repair.  can't find the schematic, but use the re-drawn by Joe Piazza(sp?)  the original will have you chasing rabbits forever

[dragonworks]

That amp is way beyond me. Nice conversation piece though. I can't do much. The only things I have really fixed by troubleshooting was my tremolo circuit in a Peavey Delta blues and the graphic eq section of a Peavey Mark IV bass amp. The Mark IV had sockets for the IC chips which made it so much easier. I dabble a lot but never really get anywhere and I bought all this test equipment and all these books, but you can only get so far with books. The schematic for the echo twin is in the cabinet, who know if it is correct or not?
J.D.

[HotBluePlates]

Picked up a basket case Ampeg Echo Twin.  ... it will never be fixed. ...

One Speed/Intensity knob for the tremolo, or two?

If two sets of trem knobs, mentally simplify the amp:  you have two complete tweed Deluxe amps in one cabinet.  Each of those Deluxe amps has tremolo (but not exactly the way Fender did it when they added tremolo to the tweed Deluxe to create the Tremolux).  The speaker of the 1st Deluxe also drives a reverb tank, which then feeds the 2nd Deluxe amp.

Simple if you break it down into pieces.

[sluckey]

The schematic for the echo twin is in the cabinet, who know if it is correct or not?

I would trust it.

[dragonworks]

"Simple if you break it down into pieces."
Everything is simple and easy when you know how to do it.  Easier said than done. I was a gymnast in high school. I could tell you the high bar moves are simple, doesn't take that much strength, just the right moves at the right time. I could even show you how. Then I could watch you get up their and break your arse lol. I am a retired CNC prgrammer and a class A machinist, I could tell you that is pretty easy also. I can't even fix the reverb circuit in my Magnatone M15 and this one is a total basket case. I haven't really looked at it since I bought it. The amp is out of the case and in a trunk. I will have to clear off the trunk, open it up and take a look. I also have my Yamaha O2R96 mixer opened up and boards removed waiting for parts on back order. The basement is starting to look like a junk yard.

[Keppy]

Sounds like a fun project to me. I got a Gemini II last month to get my Ampeg fix. I wanted to build one, but the parts would've run me more than a vintage one, so I just bought one knowing I'll probably have to fix it someday anyway.


Hope you get a chance to fire it up!

[dragonworks]

It might be fun when you have the experience and know what you are doing. When you don't it eventually only gets frustrating. It is fun up to that point, then I have to let it go for a few weeks and then get back to it when no longer frustrated, have some fun, then repeat the cycle. You can only learn so much from reading books and there is no one near me that can mentor me. I just retired and the EEs at work couldn't help me, they didn't know what a tube is.

[66Strat]

With patience, you can do it. Take detailed pictures of the circuit with all of the components in place. Replace one component at a time. Unsolder, remove, replace. Use the pictures that you took for reference. Using this methodology, you can work on the amp at your leisure.

[dragonworks]

Many component are missing. I will take some pics when I dig it out and post them so we can all have a good laugh.

[dragonworks]

When I try and post pics it says please copy all your text first? I went to the how to post attachments and it mentions nothing about that?

[sluckey]

When I try and post pics it says please copy all your text first? I went to the how to post attachments and it mentions nothing about that?

Just ignore that warning. Several years ago the forum software was misbehaving and occasionally when you attached a pic and then clicked on the post button all the text you had just typed would disappear. That problem has been resolved for a long time now.

But if you feel you must copy all your text just place your mouse cursor at the beginning of the text. Hold down the mouse left button and drag to the end of the text to select it. Then hoover the cursor over the selected text, right click, and select copy to put the text on Window's clip board. This is strictly a Window's operation. Now if something goes wrong and all your text disappears, no worry, because you have it all available on the clip board and can easily paste back into the text box.

[dragonworks]

Ampeg pics

[dragonworks]

more, these pics are big I guess

[dragonworks]

more pics, I don't know how to downsize them, bear with me

[dragonworks]

more

[dragonworks]

more

[dragonworks]

just for fun

[dragonworks]

The Maggie

[dragonworks]

more fun, and to top it off, I still have a Gemini VI in the trunk that needs work

[dragonworks]

do I have a bunch of sheet or what?

[dragonworks]

There is a dimension knob on channel two of the echo twin, I guess it is for either reverb or tremolo? What do you think guys, should I try and fire her up or what?

[dragonworks]

In my defense I must say I just moved into this house at the end of June. Had everything on one side of the basement then moved it to the other side. On top of that, four months earlier I had just moved everything from my house of 22 years in NY to  Big Stone Gap Va. Then we decided to sell that house and buy the one I am now in and moved it all again. Not to bad for a seventy year old man I think? I wasn't sure I had it in me. My elbows are paying for it though. I now have a bone spur or something sticking out of the right one and they both hurt. I WILL get around to straightening it out down there sooner or later. Anyone who has lived in one home for over twenty years knows how much junk one can gather.

[66Strat]

There is a dimension knob on channel two of the echo twin, I guess it is for either reverb or tremolo? What do you think guys, should I try and fire her up or what?

The dimension control is for the reverb. It looks like you have a Super Echo Twin amp. There is a schematic redrawn by Joe Piazza on this site. https://el34world.com/charts/Schematics/files/Ampeg/Ampeg_et2b_superechotwn.pdf

My recommendation would be to replace the electrolytic capacitors in the power supply before putting new tubes in. Test the coupling caps for leakage and replace as necessary.

New production 7591 tubes are manufactured by JJ and New Sensor. New Sensor makes a 7591 under both the EH and Tung-Sol brands.
http://tronola.com/html/7591a_tubes.html
https://www.tubesandmore.com/search/node/7591?cats%5B0%5D=1

Flip Tops carries replacement output transformers. They have a Heyboer clone of an original OT.
https://www.fliptops.net/catalog/p-100605/output-transformer-ot151a-ot151b-for-many-ampegs-out-of-stock
It looks like the OTs are temporarily out of stock. Depending upon when/or if they are restocked, you may need to find a different OT. I have no idea what the transformer specs are for the original output transformer. The Sylvania 7591 tube data sheet references 6K6 for a primary load.
https://frank.pocnet.net/sheets/168/7/7591.pdf

[dragonworks]

I have other fish to fry before I start meddling with the Echo Twin. That and I am kinda tight on the monetary end at the moment.

[thetragichero]

looks like a fun project!

[dragonworks]

looks like a fun project!

I am tempted to report you to the moderator lol.

[Willabe]

looks like a fun project!

I am tempted to report you to the moderator lol.