Search found 1648 matches

by TUBEDUDE
Wed Mar 27, 2024 11:11 am
Forum: Garage Talk
Topic: I bought a solid walnut apartment. Uh, speaker cabinet.
Replies: 27
Views: 926

Re: I bought a solid walnut apartment. Uh, speaker cabinet.

I think I'd build another cabinet and resaw that gorgeous wood into guitar tops and backs!
by TUBEDUDE
Tue Mar 26, 2024 12:25 am
Forum: Garage Talk
Topic: What's for supper?
Replies: 66
Views: 2195

Re: What's for supper?

Guys, I miss the salt- and fat-free steamed vegetables and tofu in your daily diet :mrgreen: We got lots of spinach and lettuce but no one wants to see pics of that. Tofu will never ever touch my lips. I'm trying to grow some broccoli and cauliflower for the first time but it's not going good so fa...
by TUBEDUDE
Mon Mar 25, 2024 1:43 pm
Forum: Speakers and Cabinets
Topic: Cabinet made of OSB instead of pine
Replies: 13
Views: 406

Re: Cabinet made of OSB instead of pine

That's pretty much its value.
by TUBEDUDE
Sun Mar 24, 2024 3:00 pm
Forum: Technical Discussion
Topic: The Lost Art of Cable Lacing
Replies: 16
Views: 408

Re: The Lost Art of Cable Lacing

You've done well R.G. if you landed a NASA gig you might have been too busy to have shared your extensive solid state knowledge with us over the last several decades. Geofex is a valued resource and has aided thousands in accessing the intricacies of the pedal world.
by TUBEDUDE
Sun Mar 24, 2024 2:49 pm
Forum: Technical Discussion
Topic: Power filter schematic change help
Replies: 11
Views: 195

Re: Power filter schematic change help

Maybe space requirements only allowed certain size caps in the designated area. Or Weber got great pricing on smaller caps. Hifi guys frequently use a combination of caps for faster response, but they are typically usually smaller values, and differing construction. For instance paralleled 20uF and ...
by TUBEDUDE
Sat Mar 23, 2024 6:13 pm
Forum: Technical Discussion
Topic: Flash seen from bottom of 12AT7 PI socket
Replies: 22
Views: 452

Re: Flash seen from bottom of 12AT7 PI socket

A bit extreme possibly. But you might get a few more hours from them before the heater boils away.
by TUBEDUDE
Sat Mar 23, 2024 6:09 pm
Forum: Technical Discussion
Topic: The Lost Art of Cable Lacing
Replies: 16
Views: 408

Re: The Lost Art of Cable Lacing

If you had engineered at Bell, they would have been wired right, and that 400Hz inverter squeal wouldn't be in the headsets. 🙂
by TUBEDUDE
Fri Mar 22, 2024 5:41 pm
Forum: Speakers and Cabinets
Topic: Cabinet made of OSB instead of pine
Replies: 13
Views: 406

Re: Cabinet made of OSB instead of pine

The local mall carries a nice clear SPF from New Zealand.
No knots, good grain, makes good cabinets.
20221207_190536.jpg
by TUBEDUDE
Fri Mar 22, 2024 5:00 pm
Forum: Technical Discussion
Topic: The Lost Art of Cable Lacing
Replies: 16
Views: 408

Re: The Lost Art of Cable Lacing

We laced all wires in aircraft tailbooms but I don't want them closer than necessary in an amp.
by TUBEDUDE
Thu Mar 21, 2024 1:13 am
Forum: Technical Discussion
Topic: Heater Wires - Elevate or Twist?
Replies: 18
Views: 586

Re: Heater Wires - Elevate or Twist?

didit wrote: Tue Mar 19, 2024 9:29 pm Series connected pairs run well on 12.6V.

..
Fair point!
by TUBEDUDE
Tue Mar 19, 2024 8:12 pm
Forum: Technical Discussion
Topic: Flash seen from bottom of 12AT7 PI socket
Replies: 22
Views: 452

Re: Flash seen from bottom of 12AT7 PI socket

I have Mullards and an odd Telefunken that flash. Decades of use with no issues. The plate voltage issue may be a small brown out or dip in the line voltage. A small line voltage change percentage wise shifts B+ up or down a fair amount.
by TUBEDUDE
Tue Mar 19, 2024 8:01 pm
Forum: Technical Discussion
Topic: Heater Wires - Elevate or Twist?
Replies: 18
Views: 586

Re: Heater Wires - Elevate or Twist?

Power tubes like 6 Volts.
by TUBEDUDE
Tue Mar 19, 2024 10:24 am
Forum: Technical Discussion
Topic: Heater Wires - Elevate or Twist?
Replies: 18
Views: 586

Re: Heater Wires - Elevate or Twist?

Well it doesn't matter a great deal on low gain builds. As more stages are used, the hum/noise floor increases, requiring adoption of these strategies up to a full D.C. heater supply for preamp tubes.
by TUBEDUDE
Mon Mar 18, 2024 5:10 pm
Forum: Technical Discussion
Topic: Heater Wires - Elevate or Twist?
Replies: 18
Views: 586

Re: Heater Wires - Elevate or Twist?

Elevating fights hum by eliminating hum induced in the cathode by the heater.
Twisting reduces hum by reducing radiated hum, by
, as RJ said, antiphase nulling, capacitance to ground, etc.
So both strategies combined will give less hum.
by TUBEDUDE
Fri Mar 15, 2024 11:36 am
Forum: Technical Discussion
Topic: Lowering B+ on Single ended amp with Choke input
Replies: 9
Views: 260

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

A choke input filter should have a very small cap at the input to keep a small voltage on the inductor between cycles to avoid a complete collapse of the magnetic field, and the attendant noise from the current dump.