Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: W5FH on April 09, 2023, 08:16:55 pm
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Might I ask some folks here about this interesting reverb circuit in the Ampeg ReverberRocket. Attached is the schematic. I have been researching ways to tap off and recombine the reverb signals, in lieu of the standard Fender method of doing it across a 3.3 meg resistor with bright cap. My last 2 builds incorporated the Astroverb preamp which used a common anode mixer to recombine wet reverb signal with dry signal.
It appears to me in the ReverberRocket circuit the first triode of V2 is splitting the amplified dry signal -- the plate component goes to V3 first triode (reverb tank driver) and the cathode component goes through 22K resistor to cathode of second triode in V2. It appears this second triode of V2 is a mixer with the dry signal applied to cathode and the wet reverb signal (from V3 reverb tank recovery triode) applied to the grid.
I ask this to get opinions on how this reverb circuit sounded in this amp. Am studying the different circuits and open to others suggestions. I am intrigued by the method used in the Astroverb however that is a fairly specialized amplifier made more for a nice crunch tone with limited clean headroom. Looking more at clean designs here.
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I can't say about the Rocket but my Magnatone M10A has a very similar reverb circuit. Sounds very nice, but not splashy like the typical Fender.
http://sluckeyamps.com/magnatone/Magnatone_M10A.pdf (easier to follow on page 4)
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It appears to me in the ReverberRocket circuit the first triode of V2 is splitting the amplified dry signal -- the plate component goes to V3 first triode (reverb tank driver) and the cathode component goes through 22K resistor to cathode of second triode in V2. It appears this second triode of V2 is a mixer with the dry signal applied to cathode and the wet reverb signal (from V3 reverb tank recovery triode) applied to the grid.
You got it!
I ask this to get opinions on how this reverb circuit sounded in this amp.
I suppose it can be as strong as a Fender. But lower settings sound more akin to a plate reverb (though not quite as nice as an actual plate).
Here's a 1962 R-12-R Reverberocket. I don't recall where I set the reverb for the clip below, but it was probably a bit below halfway:
https://soundcloud.com/hotblueplates/next-time-ampeg-rr
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I can't say about the Rocket but my Magnatone M10A has a very similar reverb circuit. Sounds very nice, but not splashy like the typical Fender.
http://sluckeyamps.com/magnatone/Magnatone_M10A.pdf (http://sluckeyamps.com/magnatone/Magnatone_M10A.pdf) (easier to follow on page 4)
No reverb Xfmr?
What type of tank does it use?
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Gibbs, similar or equilivant to Accutronics 4FBxxxx
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Many thanks for the replies and information, and thank you Hot Blue Plates for the sound clip!