Risson ETA-100
Moderators: pompeiisneaks, Colossal
Risson ETA-100
I picked up on EBAY to mess around with. This thing is frigin' HEAVY!!! Does anyone have a Schematic, info or any paperwork on it?
Under filter cap lid it says "ARGONOT"
Thanks in advance!
Under filter cap lid it says "ARGONOT"
Thanks in advance!
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- pompeiisneaks
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Re: Risson ETA-100
Sadly I'm finding nothing on the googles. Maybe you need to create the first one Does it look like a form of a marshall in some way? It seems like many of the posts I did find indicate a marshall style circuit?
~Phil
~Phil
tUber Nerd!
Re: Risson ETA-100
Sure looks Fendery, with the fiber board, doghouse, white Mallory bypass caps, etc.
I build and repair tube amps. http://amps.monkeymatic.com
Re: Risson ETA-100
Interesting amp.
Here's the link I found to Risson amps and Bob Rissi. Definitely Fender heritage.
http://www.rissonamplifiers.com
Here's the link I found to Risson amps and Bob Rissi. Definitely Fender heritage.
http://www.rissonamplifiers.com
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Bryan
Bryan
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Re: Risson ETA-100
Those EL34s are cathode biased?
Those are very large Transfomers for a 50 to 70 watt RMS amp, so I bet its heavy!
Those are very large Transfomers for a 50 to 70 watt RMS amp, so I bet its heavy!
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Re: Risson ETA-100
What little info I found out, it takes 2- KT88s OR 6550s
with 3- 12AX7s
I had emailed Risson Amps for some info but no response yet.
with 3- 12AX7s
I had emailed Risson Amps for some info but no response yet.
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Re: Risson ETA-100
I was guessing 34s because I see pins 1 and 8 going to ground , but with those size Trans 88s seem like a better fit!
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Re: Risson ETA-100
That amplifier clearly had four big bottles and three little bottles originally. It was almost certainly a 100W amp given the four big bottles, the transformer sizes, and the "100" in the name. There is a high probability that he used 6L6's since this is a U.S.A. amplifier modeled after Fender. There is a bias tap and and bias circuit for fixed bias.
I would strip that thing bare and use the chassis and iron to make a 100W amp of choice.
I would strip that thing bare and use the chassis and iron to make a 100W amp of choice.
Re: Risson ETA-100
Ten Over thanks for the info.Ten Over wrote: ↑Mon May 07, 2018 8:49 pm That amplifier clearly had four big bottles and three little bottles originally. It was almost certainly a 100W amp given the four big bottles, the transformer sizes, and the "100" in the name. There is a high probability that he used 6L6's since this is a U.S.A. amplifier modeled after Fender. There is a bias tap and and bias circuit for fixed bias.
I would strip that thing bare and use the chassis and iron to make a 100W amp of choice.
Do you think someone knocked it down to a 50W head by removing the 2 other tubes & sockets ?
Bob Rizzi was the owner/builder of these amps. He did work for Fender so hence the looks.
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Re: Risson ETA-100
Absolutely. Look at the heater wires coming out of the transformer. They were originally twisted and went to the power tube that now has a plastic plug in the hole. One wire managed to make it to the second tube socket when straightened out, but the other had to go to a terminal strip with a new wire continuing on to the tube.
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Re: Risson ETA-100
I did a search on the ETA-100 and I now believe it originally had 6550's in it.
Re: Risson ETA-100
A pair of KT-88s can push 100+ watts through speakers if the B+ is high enough and the load is right.
https://drtube.com/datasheets/kt88-sed2001.pdf
Actual mileage may vary, of course. The transformers are the biggest variables as usual.
https://drtube.com/datasheets/kt88-sed2001.pdf
Actual mileage may vary, of course. The transformers are the biggest variables as usual.
Re: Risson ETA-100
Thanks!nworbetan wrote: ↑Tue May 08, 2018 3:31 am A pair of KT-88s can push 100+ watts through speakers if the B+ is high enough and the load is right.
https://drtube.com/datasheets/kt88-sed2001.pdf
Actual mileage may vary, of course. The transformers are the biggest variables as usual.
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Re: Risson ETA-100
If it is reworked to use 6L6 tubes and is applying more then 510 volts on the plates then your gonna need really good 6L6s in there!
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!