Risson ETA-100

[Junkin8ez]

14s-l1600.jpg

9s-l1600.jpg

[andresound]

Those blue coupling caps are definitely late 60’s - early 70’s fender

[didit]

Seeing Dumble Small Special lurking in that pile of rubble.

Best .. Ian

[Cameron]

Bob liked the 8417 tube ....and It is a cool tube.....it's probably what was in this amp originally then he realised the 6550 was more common tube and started to use them instead...... He used to work for Fender ....when Fender shut down production for a bit in the US in 82 and laid off everyone ..Bob grabbed all the unfinished amps and parts he could ...most of this stuff would have been tossed anyway....and started to make his own amps using these parts. Some sounded good...some pretty bad and the work ..soldering and general build was not so good....Lots of LA bands used them. He had some deal ..where you could trade your Marshall amp and get a cheap price for your new Risson amp ....haha..
The transformers are really good ...most are from the higher wattage amps like the 75 and 140 and others from this time. Those had pretty high plate voltages. Some might have extra windings for switching and other stuff.
Bob had some weird preamp he designed...I just remember it being odd the way he did things ...if you have time ..can you draw up a schematic of this? ...I'd be curious to see what's going on in it.. It's been many years since I've seen one or worked on one. In 83 I had an oddball ETA ...but I've never seen another one like it ...It looked more like a bassman head instead of the Marshall style look ....that amp sounded good ....my friend had one like yours and it sounded like a Twin on 10 with too much bass in the preamp ...just fuzzy mushy gain ..no definition.
Because it has good transformers ...it's a great platform to make something cool or just use the transformers for another build

[Scumback Speakers]

Pretty sure I have either an ETA 100 or ETA 60 in the shop. I need to go check and see exactly what it is, though.

[Junkin8ez]

Thanks for the info! Very helpful. I did get an email response from Bob to give him a call. Unfortunately time has not been on my side lately to sit down & go over it with him on the phone.

[guitarjesus]

Thanks for the info! Very helpful. I did get an email response from Bob to give him a call. Unfortunately time has not been on my side lately to sit down & go over it with him on the phone.

Did you ever figure it out? I used to have an ETA 50 back in the day, and it looked identical. Pretty sure Bob just used the 100 watt chassis for 50 watt amps and just plugged the octal holes. Mine was microphonic like a buzzsaw. Only paid $50 at a pawn shop, so I trashed it. Wish I didn't, Bob took my LTA and got it working awesome, I should have let him do the same with that amp.

[Junkin8ez]

Nope, Did not mess with it yet.It's on the shelf.