Hello everyone!
I have been hard at work trying to kludge together a bunch of those cool Dumble ideas into one amp. My goal was to make something that was somewhat like a Steel String Singer with Martin's step filters, low plate OD channel, and post phase inverter cathode follower using Martin's improved cathode follower driver circuit. I will also use the Metroamp solid state FX loop, which uses a pair of LND150s as a buffer and return stage.
Note that the clean preamp is more ODS based, and without Jazz setting or PAB. I did integrate the preamp from an Echoplex EP3 in lieu of the normal D style FET preamp.
I opted (for space reasons) to run a pair of 6550s at around 100W as opposed to a quad of 6L6s.
Inevitably there are some compromises - The step filters are plate driven, followed by a cathode follower - mixer stage in a SSS amp. In trying to keep this thing from using 8 preamp tubes, I've opted to move the filters to the end of the circuit before the send on the loop - The idea that the loop's buffer will play double duty for FX and for the filters - then the return of the loop exits to the top of the master volume control.
I've tentatively wired in a loop bypass relay on the schematic, but that might go away when i build it.
I would love to have some feedback here from the group on this schematic. I've attached it below. I've also got a layout pretty well underway
Let me know what y'all think
Dustin
Steel String Singer+Overdrive Reverb+Post PI Cathode Follower Hybrid thread
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Steel String Singer+Overdrive Reverb+Post PI Cathode Follower Hybrid thread
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Re: Steel String Singer+Overdrive Reverb+Post PI Cathode Follower Hybrid thread
Excited to hear how this sounds when its done!
I don't see were the signal goes through the 1M resistor and then the 68 K ( or slightly higher like 150K) to ground.
This comes off of v1B in the SSS/JM amp. Maybe this is not being used since you are incorporating the OD channel?
Edit. Ok I think I see it now, its actually 470K on the SSS amp and not 1M and then you have the signal going into v5a.
Cheers
Guy
I don't see were the signal goes through the 1M resistor and then the 68 K ( or slightly higher like 150K) to ground.
This comes off of v1B in the SSS/JM amp. Maybe this is not being used since you are incorporating the OD channel?
Edit. Ok I think I see it now, its actually 470K on the SSS amp and not 1M and then you have the signal going into v5a.
Cheers
Guy
Re: Steel String Singer+Overdrive Reverb+Post PI Cathode Follower Hybrid thread
This looks like a great project. I'd love to see the lay out.
Eric
Eric
Eric
1949 Zenith, Zenith Toggle Recoil, Zenith 55 & 440
1949 Zenith, Zenith Toggle Recoil, Zenith 55 & 440
Re: Steel String Singer+Overdrive Reverb+Post PI Cathode Follower Hybrid thread
Your reverb send could end up with too much gain since your feeding it after V1B (series) instead of before it (parallel) as Dumble does....
TT
TT
Re: Steel String Singer+Overdrive Reverb+Post PI Cathode Follower Hybrid thread
Tictac,
I am borrowing heavily from the JM Sig amp for the clean preamp and some of the reverb. I know on the SSS it's taken from after the first stage, and on the ODR/JM Sig amp it's after the 2nd gain stage.
I'll leave some space to play around with it both ways when I start to build it.
Sent from my Moto G (4) using Tapatalk
I am borrowing heavily from the JM Sig amp for the clean preamp and some of the reverb. I know on the SSS it's taken from after the first stage, and on the ODR/JM Sig amp it's after the 2nd gain stage.
I'll leave some space to play around with it both ways when I start to build it.
Sent from my Moto G (4) using Tapatalk
Re: Steel String Singer+Overdrive Reverb+Post PI Cathode Follower Hybrid thread
The JM Sig schematic posted on TAG shows the reverb being tapped before the 2nd stage. We are talking about the TwoRock amp, correct?
TT
TT
Re: Steel String Singer+Overdrive Reverb+Post PI Cathode Follower Hybrid thread
Sorry, I should clarify!
Topology wise, this amp looks a lot like Overdrive Reverb #60. The verb entrance comes after the clean channel OR the OD channel, unlike the other Dumbles that don't have an OD channel. I used JM sig amp preamp values in the clean channel. OD channel is a lot like #60.
I built a version of ODR#60 with the clean channel of the JM sig amp and it sounded absolutely killer. This schemo is building upon those ideas, and implementing the cathode follower/filters from the SSS.
Sent from my Moto G (4) using Tapatalk
Topology wise, this amp looks a lot like Overdrive Reverb #60. The verb entrance comes after the clean channel OR the OD channel, unlike the other Dumbles that don't have an OD channel. I used JM sig amp preamp values in the clean channel. OD channel is a lot like #60.
I built a version of ODR#60 with the clean channel of the JM sig amp and it sounded absolutely killer. This schemo is building upon those ideas, and implementing the cathode follower/filters from the SSS.
Sent from my Moto G (4) using Tapatalk