Search found 1073 matches
- Thu Mar 21, 2024 6:15 pm
- Forum: Dumble Discussion
- Topic: Choke Selection Question-Dumble Reverb
- Replies: 15
- Views: 655
Re: Choke Selection Question
... how much more current draw does the voltage doubler circuit put on the transformer? I'd say at least four times the DC current, but the waveform is spiky and will peak at a much higher value depending upon the DC resistance and reservoir capacitors. For this case I'm getting 65 mA peak and 25mA...
- Mon Mar 18, 2024 2:09 am
- Forum: Dumble Discussion
- Topic: Choke Selection Question-Dumble Reverb
- Replies: 15
- Views: 655
Re: Choke Selection Question-Dumble Reverb
Hey look at that, thanks. The only thing that I wonder about is the 300VDC rating.
CW
CW
- Sun Mar 17, 2024 3:20 am
- Forum: Dumble Discussion
- Topic: Choke Selection Question-Dumble Reverb
- Replies: 15
- Views: 655
Re: Choke Selection Question-Dumble Reverb
Although not a choke question, another interesting thing about this device is the little Triad transformer used as the reverb driver. It is a S-13X which has a primary of 25k and a secondary of 3.2 ohms driven by a 5751 tube. So a mismatch with the 8 ohm input of the reverb pan. Not sure if he was t...
- Sun Mar 17, 2024 1:46 am
- Forum: Technical Discussion
- Topic: Tweedle Dee PI - LNFB
- Replies: 32
- Views: 904
Re: Tweedle Dee LNFB
OK, so I am envious of being able to do all those calculations but did you, at some point, simply disconnect the LNFB and listen to the amp turned up? Do you hear a difference with it in and out of the circuit? If you don't hear a difference, then all the calculating may show why but if you do hear ...
- Sat Mar 16, 2024 1:54 am
- Forum: Dumble Discussion
- Topic: C-lator hum
- Replies: 170
- Views: 2881
Re: C-lator hum
Are potentiometer casings referenced to ground?
CW
CW
- Thu Mar 14, 2024 7:14 pm
- Forum: Dumble Discussion
- Topic: Choke Selection Question-Dumble Reverb
- Replies: 15
- Views: 655
Re: Choke Selection Question
Thanks Martin.
CW
CW
- Thu Mar 14, 2024 2:39 am
- Forum: Dumble Discussion
- Topic: Choke Selection Question-Dumble Reverb
- Replies: 15
- Views: 655
Re: Choke Selection Question
Martin, the primary is 60 ohms and the secondary is 235.3 ohms. I wanted a transformer that would fit the existing cut out and I needed enough filament wind for 3 preamp tubes, so the 40 mA was as much as we could get for secondaries. Bill at Heyboer said he also beefed up the primary a bit. For a 6...
- Wed Mar 13, 2024 2:56 am
- Forum: Dumble Discussion
- Topic: Choke Selection Question-Dumble Reverb
- Replies: 15
- Views: 655
Re: Choke Selection Question
Thanks guys. I can say that the device is a three tube stand alone reverb that Dumble did in the early eighties. It uses two 12ax7s and one 5751 as the reverb driver tube. The cut out for the power transformer is the venerable Triad R-2C, so 15mA DC. The hole spacing for the choke is 1 3/4", pretty ...
- Tue Mar 12, 2024 2:08 am
- Forum: Dumble Discussion
- Topic: Dumbleator Filtering
- Replies: 2
- Views: 237
Re: Dumbleator Filtering
Thank you sir. Yeah I have built a few Dumbleators with the 47uf caps with good results. Not sure why I started to wonder about that other than seeing Brandons original post where he stated that they were 100uf. However, that post was almost 20 years ago.
CW
CW
- Tue Mar 12, 2024 1:23 am
- Forum: Dumble Discussion
- Topic: Choke Selection Question-Dumble Reverb
- Replies: 15
- Views: 655
Choke Selection Question-Dumble Reverb
Hello, I have a device that I am restoring and it was missing the power transformer and the choke. I sorted out the power transformer but I could use some help on selecting a choke. I have this in the Dumble section because it is a Dumble device but unfortunately I cannot share much more than that r...
- Thu Mar 07, 2024 3:05 am
- Forum: Dumble Discussion
- Topic: Dumble ODS #22
- Replies: 15
- Views: 551
Re: Dumble ODS #22
The low plate classic was originally owned by Jackson Browne and lent to SRV.
CW
CW
- Sat Mar 02, 2024 4:32 am
- Forum: Dumble Discussion
- Topic: Dumbleator Filtering
- Replies: 2
- Views: 237
Dumbleator Filtering
Hello, I am going way back on this question. The main filtering everyone including myself seems to be using are the two 47uf in series per the schematic in the file section. However, I found a real early Brandon post where he stated that the first two caps were 100uf. So I am wondering, did we decid...
- Fri Feb 16, 2024 2:02 am
- Forum: Technical Discussion
- Topic: New Astron caps?!?
- Replies: 22
- Views: 696
Re: New Astron caps?!?
If you want to spend a bunch of money and probably get a good sounding Astron style cap.
http://www.tweeddeluxe.com/recpro-capacitors.cfm
CW
http://www.tweeddeluxe.com/recpro-capacitors.cfm
CW
- Thu Oct 26, 2023 1:20 am
- Forum: Fender Discussion
- Topic: Current production Fender ‘65 Deluxe Reverb help
- Replies: 4
- Views: 10515
Re: Current production Fender ‘65 Deluxe Reverb help
So here is what is going on with this amplifier. Fender has made changes to the circuit that apparently the service department wasn't even aware of. One of the rectifier filament leads (yellow) goes to the tube socket the other (blue) goes to the circuit board. Between the rectifier filament lead an...
- Mon Oct 16, 2023 11:16 pm
- Forum: Dumble Discussion
- Topic: 2nd gen chassis and pcb design?
- Replies: 60
- Views: 25296
Re: 2nd gen chassis and pcb design?
Yes, Overdrive Special is trademarked. As is Dumbleator and Overdrive Reverb. The trademarks are held by the Dumble estate.
CW
CW