Search found 21 matches
- Wed Mar 06, 2024 11:35 am
- Forum: Marshall Discussion
- Topic: Cathode follower and previous stage in different tubes?
- Replies: 1
- Views: 377
Cathode follower and previous stage in different tubes?
Usually see the CF and previous stage in same tube, but for purposes of a mod I'm thinking of, would be easier if in different tubes. Any good reason NOT to do that?
- Wed Mar 06, 2024 11:29 am
- Forum: Marshall Discussion
- Topic: Marshall Hot Rod diode clipping connection method difference?
- Replies: 8
- Views: 926
Re: Marshall Hot Rod diode clipping connection method difference?
The 220n cap on the Jose mod blocks dc from the CF so there is no DC on the master, which would make the master scratchy, and also put it in parallel with the 100k Rk (for purposes of DC). You have to also realize that the 220n cap is also in series with your tone caps, which DOES slightly change th...
- Tue Dec 26, 2023 3:38 am
- Forum: Dumble Discussion
- Topic: Low Plate clean, High plate OD?
- Replies: 2
- Views: 9239
Low Plate clean, High plate OD?
Anyone done that? If so, opinion?
I much prefer low plate classic cleans, but I can see the argument for high plate on the OD stages.
I much prefer low plate classic cleans, but I can see the argument for high plate on the OD stages.
- Tue Oct 17, 2023 9:12 pm
- Forum: Marshall Discussion
- Topic: One cathode follower, 2 tone stacks
- Replies: 10
- Views: 3790
Re: One cathode follower, 2 tone stacks
What about a 1uf cap to block the dc from the cathode follower and a relay to switch the output between the stacks? Any foreseeable issues there? The 1uf should be more than large enough to be transparent. I see what you're saying about using 2 dpdt to switch the output of each cap, but that assume...
- Tue Oct 17, 2023 9:02 pm
- Forum: Marshall Discussion
- Topic: One cathode follower, 2 tone stacks
- Replies: 10
- Views: 3790
Re: One cathode follower, 2 tone stacks
I'm not trying to tell you what to do - I may be misunderstanding, but, I'd use a 0.1µF cap to feed the A side COM of a DPDT relay... A side NO and NC would go to the two individual TSs. Jump NO of the A pole of the relay to the NC of the B pole, then jump from NC to NO. Connect the B side COM to G...
- Tue Oct 17, 2023 1:07 am
- Forum: Marshall Discussion
- Topic: One cathode follower, 2 tone stacks
- Replies: 10
- Views: 3790
Re: One cathode follower, 2 tone stacks
What about a 1uf cap to block the dc from the cathode follower and a relay to switch the output between the stacks? Any foreseeable issues there? The 1uf should be more than large enough to be transparent. I see what you're saying about using 2 dpdt to switch the output of each cap, but that assumes...
- Sun Oct 15, 2023 10:25 pm
- Forum: Marshall Discussion
- Topic: One cathode follower, 2 tone stacks
- Replies: 10
- Views: 3790
One cathode follower, 2 tone stacks
Running both stacks in a channel switching config. attached to one cathode follower, outputs switched after stack and master. Anyone done this? My questions would be: 1) resistors to isolate each stack? 2) better to do this, or put a 1uf dc blocking cap after the cathode and just switch stacks with ...
- Fri Oct 13, 2023 9:02 pm
- Forum: Marshall Discussion
- Topic: Primary impedance of original jtm 45 ot?
- Replies: 18
- Views: 7376
- Thu Oct 12, 2023 7:36 pm
- Forum: Marshall Discussion
- Topic: Primary impedance of original jtm 45 ot?
- Replies: 18
- Views: 7376
Primary impedance of original jtm 45 ot?
Anyone know the correct primary impedance on the kt66 jtm 45s? Thanks in advance.
- Thu Mar 31, 2022 9:36 pm
- Forum: Technical Discussion
- Topic: Bogner Metropolis Schematic?
- Replies: 0
- Views: 23715
Bogner Metropolis Schematic?
Anyone have one? Thanks!
- Tue Jan 11, 2022 5:14 am
- Forum: Dumble Discussion
- Topic: Changing the OD Input coupling cap to lower value on ODS to tighten it up
- Replies: 2
- Views: 622
Changing the OD Input coupling cap to lower value on ODS to tighten it up
Anyone messed with various cap values to tighten up the low end on a ODS (Assuming you like some bass in your clean tone)? What cap value did you end up with? On my HRD mod I had to drop it all the way to 500pf to get it tight, but I think that might suck too much fatness out of the ODS.
- Sat Jul 25, 2020 9:14 pm
- Forum: Technical Discussion
- Topic: Lord Valve - Current Production EL34 20W
- Replies: 3
- Views: 814
Re: Lord Valve - Current Production EL34 20W
In groove tubes parlance, "S"= JJ.
- Sat Jul 25, 2020 9:10 pm
- Forum: Technical Discussion
- Topic: Zinky Blue velvet 25 schematic
- Replies: 1
- Views: 462
Re: Zinky Blue velvet 25 schematic
No Supro similar, and the builder is an arse about schematics. I had a customer who had a few I repaired for him, I recall having to trace the relevant parts of the circuit.
- Thu May 28, 2020 11:15 pm
- Forum: Marshall Discussion
- Topic: Everything weird happens between 4 and 6AM
- Replies: 10
- Views: 1564
Re: Everything weird happens between 4 and 6AM
What are we talking about here? Adding an inductor across an Rk to try to get a specific frequency boost?
- Fri May 22, 2020 9:09 pm
- Forum: Marshall Discussion
- Topic: Everything weird happens between 4 and 6AM
- Replies: 10
- Views: 1564
Re: Everything weird happens between 4 and 6AM
I feel like I missed part of the conversation. Is there a schematic?