Search found 485 matches

by mhuss
Thu Mar 21, 2024 3:48 pm
Forum: Technical Discussion
Topic: The Lost Art of Cable Lacing
Replies: 16
Views: 391

Re: The Lost Art of Cable Lacing

I've always been a fan too, but cable ties are so much easier, lol.
by mhuss
Tue Mar 19, 2024 3:42 pm
Forum: Technical Discussion
Topic: ADA MP-1 schematic question
Replies: 2
Views: 78

Re: ADA MP-1 schematic question

Hard to say for sure without knowing what U7 and T3 are.
by mhuss
Fri Mar 15, 2024 2:28 pm
Forum: Technical Discussion
Topic: Lowering B+ on Single ended amp with Choke input
Replies: 9
Views: 247

Re: Lowering B+ on Single ended amp with Choke input

This Hammond AO-63 amp does not have any cap before the choke. It also has a tube rectifier. I agree with the previous poster, the small value cap in the newer design is really only useful there to reduce HF noise. OTOH, as you get up to 1uF, you start to have a (really weak) cap input filter. I gu...
by mhuss
Wed Mar 13, 2024 8:25 pm
Forum: Technical Discussion
Topic: F&T - Mersen
Replies: 2
Views: 162

Re: F&T - Mersen

If buy in sufficient quantity, F&T will brand the caps for you.
by mhuss
Wed Mar 13, 2024 8:23 pm
Forum: Technical Discussion
Topic: Cap value
Replies: 2
Views: 117

Re: Cap value

To amplify a bit, 151 = 15 plus 1 zero = 150. Based on the type and size the 150 is in pF.
by mhuss
Tue Mar 05, 2024 2:45 pm
Forum: Technical Discussion
Topic: PT reverse engineering problem
Replies: 11
Views: 314

Re: PT reverse engineering problem

Yeah, little high gain antennae. :roll:
by mhuss
Tue Mar 05, 2024 12:23 am
Forum: Technical Discussion
Topic: PT reverse engineering problem
Replies: 11
Views: 314

Re: PT reverse engineering problem

I think R.G. is onto something. I put a 250 ohm 25w resistor across all three combinations, and read 3.2vac (again) on one, but the other two now read almost nothing (0.007xx vac). These three wires are the only "8 amp" (6 x EL34) sized wires coming out of the transformer, so they must be the heater...
by mhuss
Sun Mar 03, 2024 2:36 am
Forum: Technical Discussion
Topic: PT reverse engineering problem
Replies: 11
Views: 314

Re: PT reverse engineering problem

There is very low resistance (< 1 ohm) between the three big wires.
by mhuss
Sat Mar 02, 2024 11:12 pm
Forum: Technical Discussion
Topic: PT reverse engineering problem
Replies: 11
Views: 314

Re: PT reverse engineering problem

You'd have to ask Sound City. :)

The upper HT winding is ~250VAC and the lower is ~325VAC (both no load).

Here's the 'left hand' side of the schematic fwiw
by mhuss
Sat Mar 02, 2024 9:57 pm
Forum: Technical Discussion
Topic: PT reverse engineering problem
Replies: 11
Views: 314

PT reverse engineering problem

I have a Partridge PT supposedly from a SC200, and the secondary windings and voltages it mostly check out as expected - but the three big wires (black, blue, green) coming out of the secondary, which one would assume are the heater winding, measure ~62VAC across two pairs and ~3.1VAC across the oth...
by mhuss
Wed Feb 28, 2024 6:50 pm
Forum: Technical Discussion
Topic: Sturdy EL34s?
Replies: 15
Views: 386

Re: Sturdy EL34s?

Thanks for the suggestions
by mhuss
Tue Feb 27, 2024 8:29 pm
Forum: Technical Discussion
Topic: Sturdy EL34s?
Replies: 15
Views: 386

Sturdy EL34s?

I have to re-tube a DR201 (6 x EL34, 650v B+). What are folks experience with current EL34 brands in a higher voltage situation (besides "boom!" :P)?

The 201 has a split supply, so the screen voltage is about 2/3 the plate voltage, which helps a bit.
by mhuss
Mon Feb 26, 2024 8:56 pm
Forum: Technical Discussion
Topic: Transformer rescue
Replies: 6
Views: 240

Re: Transformer rescue

All good information, thanks
by mhuss
Thu Feb 22, 2024 5:02 pm
Forum: Technical Discussion
Topic: Transformer rescue
Replies: 6
Views: 240

Re: Transformer rescue

Thanks for the suggestions.
by mhuss
Thu Feb 22, 2024 5:00 pm
Forum: Technical Discussion
Topic: What do you believe regarding the sound of passive components?
Replies: 185
Views: 4017

Re: What do you believe about the sound of passive components?

I think that in a controlled environment, using people with excellent hearing, you might detect some subtle differences. I would only trust double-blind tests, as humans are all too easily fooled (including themselves). I've caught myself thinking I heard a difference when adjusting the control on t...