Search found 13236 matches
- Wed May 15, 2024 1:24 pm
- Forum: Dumble Discussion
- Topic: The Much Anticipated (?) Bluesmaster Build Thread
- Replies: 58
- Views: 1762
Re: The Much Anticipated (?) Bluesmaster Build Thread
Yes. If you disconnect the PT heater leads you should measure ~150R to ground from pins 7 and 2. There are two diodes and a resistor across those pins, but that shouldn't affect the measurement significantly.
- Wed May 15, 2024 12:56 pm
- Forum: Dumble Discussion
- Topic: The Much Anticipated (?) Bluesmaster Build Thread
- Replies: 58
- Views: 1762
Re: The Much Anticipated (?) Bluesmaster Build Thread
I’ll go over everything one more time, but I’m fairly certain that I don’t. Is it safe to measure heater voltage with the leads off the socket and just hanging in the air? No problem. Measure across the leads since you have removed the ground reference. The only other thing I wonder about is the te...
- Wed May 15, 2024 11:06 am
- Forum: Dumble Discussion
- Topic: The Much Anticipated (?) Bluesmaster Build Thread
- Replies: 58
- Views: 1762
Re: The Much Anticipated (?) Bluesmaster Build Thread
Ok, replaced the heater ACTs with 150R and fired it up. Now I have 6.2vac on pin 2 and 0 on pin 7. With or without tubes you should get about 6.3 across the heater string and half of that from each side to ground. Are you sure you don't have any part of that network grounded other than the 2x 150R?
- Wed May 15, 2024 10:57 am
- Forum: Technical Discussion
- Topic: Illinois brand capacitors still bad?
- Replies: 21
- Views: 905
Re: Illinois brand capacitors still bad?
The 10u 160V IC cap's ESR is not out of line. Check the chart that came with your Peak. Are there caps with lower ESR? Sure, and in some applications such as SMPS with high ripple current it's necessary for adequate life. Those old Mallory's appear to be good, but if that amp is going to be a player...
- Tue May 14, 2024 8:10 pm
- Forum: Dumble Discussion
- Topic: The Much Anticipated (?) Bluesmaster Build Thread
- Replies: 58
- Views: 1762
Re: The Much Anticipated (?) Bluesmaster Build Thread
Do you have 150k resistors to ground from pins 2 and 7 instead of 150 ohm?
- Tue May 14, 2024 6:58 pm
- Forum: Dumble Discussion
- Topic: The Much Anticipated (?) Bluesmaster Build Thread
- Replies: 58
- Views: 1762
Re: The Much Anticipated (?) Bluesmaster Build Thread
Heater voltage was 2.9vac at pin 7 and 6.9 at pin 2 - but 6.2 measured across 2 &7; panel light consistent with this as well. Don't understand this... If pin 2 to pin 7 is 6.2, I would think pins 2 and 7 should both be ~3.1 to ground. Is the only load you have on the heater circuit the panel lamp? ...
- Tue May 14, 2024 5:14 pm
- Forum: Dumble Discussion
- Topic: 2nd Gen Build
- Replies: 59
- Views: 2678
Re: 2nd Gen Build
My thought was keep the load similar to the Second Gen to preserve its character, and allow some plus/minus on the level coming out of the OD wrt the fixed divider in the Second Gen layout. The main point is, however you do it, the Ratio control provides for adjustment of the OD output without going...
- Tue May 14, 2024 2:30 pm
- Forum: Dumble Discussion
- Topic: ODS 102 with 2x KT88s and built-in Dumbleator
- Replies: 32
- Views: 866
Re: ODS 102 with 2x KT88s and built-in Dumbleator
Looks good now.
- Tue May 14, 2024 11:46 am
- Forum: Technical Discussion
- Topic: Illinois brand capacitors still bad?
- Replies: 21
- Views: 905
- Tue May 14, 2024 11:26 am
- Forum: Technical Discussion
- Topic: Does a 'bright cap' really boost highs?
- Replies: 23
- Views: 5119
Re: Does a 'bright cap' really boost highs?
Correct. The cap is a bypass around the upper part of the resistive divider.
- Tue May 14, 2024 11:16 am
- Forum: Technical Discussion
- Topic: Does a 'bright cap' really boost highs?
- Replies: 23
- Views: 5119
Re: Does a 'bright cap' really boost highs?
I finally got a load of caps to try in my 5F1 based amp. Quick question: Do I put the bright cap between lugs 1 and 2 of the Volume pot, or between lugs 2 and 3? I've seen it mentioned both ways. Or doesn't it matter? Might depend on how you number the lugs. If lug 3 is the input, lug 2 is the wipe...
- Tue May 14, 2024 11:13 am
- Forum: Dumble Discussion
- Topic: ODS 102 with 2x KT88s and built-in Dumbleator
- Replies: 32
- Views: 866
Re: ODS 102 with 2x KT88s and built-in Dumbleator
So, I'm just looking at the FET circuit and the Relay power supply. If I use the Triad F-216X 12VAC supply, it looks like I use a FWB rectifier. I need a TO220 Regulator? Any recommendations? It just needs to regulate that 12VDC? LM7812 regulator as shown on the D schematics will be fine. Looking a...
- Mon May 13, 2024 6:25 pm
- Forum: Dumble Discussion
- Topic: ODS 102 with 2x KT88s and built-in Dumbleator
- Replies: 32
- Views: 866
Re: ODS 102 with 2x KT88s and built-in Dumbleator
Am I seeing right that I may be able to take my heater supply and use it to feed the power for the relay switching? Or is that generally more trouble than using one of these 12V transformers? I think it's simpler to use a separate transformer for the relays. You can use 12VAC and a bridge, or 6VAC ...
- Mon May 13, 2024 4:47 pm
- Forum: Dumble Discussion
- Topic: ODS 102 with 2x KT88s and built-in Dumbleator
- Replies: 32
- Views: 866
Re: ODS 102 with 2x KT88s and built-in Dumbleator
... and trying to figure out what transformer works well for the relay power... Raoul Duke posted a data sheet for this small Triad for relay power using a FWB: https://www.mouser.com/ProductDetail/Triad-Magnetics/F-216X?qs=b1anAsPanWyvCrSmsu4ZQw%3D%3D This Hammond is also a possibility for FWB: ht...
- Mon May 13, 2024 4:16 pm
- Forum: Dumble Discussion
- Topic: ODS 102 with 2x KT88s and built-in Dumbleator
- Replies: 32
- Views: 866
Re: ODS 102 with 2x KT88s and built-in Dumbleator
There's info on these in the ODS boards .pdf here https://ampgarage.com/forum/viewtopic.php?f=5&t=29630