Search found 15794 matches

by Nick
Thu May 23, 2024 2:54 pm
Forum: Assorted Stuff
Topic: Zero emission road vehicles.
Replies: 935
Views: 431503

Re: Zero emission road vehicles.

Yep, the introduction of EV's can't fix stupid.
by Nick
Thu May 23, 2024 11:54 am
Forum: Assorted Stuff
Topic: Zero emission road vehicles.
Replies: 935
Views: 431503

Re: Zero emission road vehicles.

Checking, the range doesn't sound like it will have come as a surprise to anyone, VW quote a WLTP range of 82 miles. I would guess that whoever decided to buy them knew that and had looked at the daily millage done by their previous fleet. Nothing wrong with a 50 mile range if they only get driven 4...
by Nick
Mon May 20, 2024 4:48 pm
Forum: General Vinyl
Topic: 60Hz oscillator for turntables (also produces three phase)
Replies: 17
Views: 992

Re: 60Hz oscillator for turntables (also produces three phase)

Even better just replace motor with single phase one, but I was just pointing out that 3kW for £500 is hard to match with any valve solution, even before we look at the efficiency question.
by Nick
Mon May 20, 2024 3:18 pm
Forum: General Vinyl
Topic: 60Hz oscillator for turntables (also produces three phase)
Replies: 17
Views: 992

Re: 60Hz oscillator for turntables (also produces three phase)

The link says "4 x 1600 Watts @ 2 Ohms; 2 x 3000 Watts @ 4 Ohms"

So that's either 4 * 56v or 2 * 109v
by Nick
Mon May 20, 2024 12:37 pm
Forum: General Vinyl
Topic: 60Hz oscillator for turntables (also produces three phase)
Replies: 17
Views: 992

Re: 60Hz oscillator for turntables (also produces three phase)

Three phases from Morgans circuit + one of these

https://www.behringer.com/product.html? ... e=0105-ABE

And three step up autoformers to match the motor voltage should do the job.
by Nick
Sun May 19, 2024 11:58 am
Forum: General Vinyl
Topic: 60Hz oscillator for turntables (also produces three phase)
Replies: 17
Views: 992

Re: 60Hz oscillator for turntables (also produces three phase)

TDA7293 will be fine for 24v if needed.
by Nick
Fri May 17, 2024 10:18 pm
Forum: Valves
Topic: Dying Rectifier?
Replies: 28
Views: 1739

Re: Dying Rectifier?

Looks like the GZ33 was the guilty party. Incredible but true! :shock: I've just looked up GZ37 prices. Blimus! And I looked up the GZ33 data sheet. Mea culpa. Yes, a GZ37 is actually less hungry in heater current than a GZ37. I've just looked at eBay. 2 x NOS Mullard GZ33, original boxes, 'never u...
by Nick
Fri May 17, 2024 5:29 pm
Forum: Valves
Topic: Dying Rectifier?
Replies: 28
Views: 1739

Re: Dying Rectifier?

Well, you may find a lot of switching noise on the heater. There is no free lunch when it comes to AC to DC, you only get the full 1.414 times with no load.

And you have the voltage lost across the bridge diodes Vf as well to deal with(out)
by Nick
Fri May 17, 2024 9:40 am
Forum: Valves
Topic: Dying Rectifier?
Replies: 28
Views: 1739

Re: Dying Rectifier?

I think he means a DIN rail relay socket. This sort of thing https://uk.rs-online.com/web/p/relay-sockets/0402147
by Nick
Thu May 16, 2024 10:11 pm
Forum: Valves
Topic: Valve amplifier service
Replies: 200
Views: 100142

Re: Valve amplifier service

Or as said you could use Audacity to generate test waveforms, I have done similar.
Yep, but not ideal for square waves, very dependent on your DAC and you wont get the fast risetime that we want to push the amplifier.
by Nick
Tue May 14, 2024 2:20 pm
Forum: Speakers
Topic: TG "The Loudspeaker" Build (Sort of)
Replies: 180
Views: 19266

Re: TG "The Loudspeaker" Build (Sort of)

Though the 25kg H&S limit must be in danger!
Image
by Nick
Tue May 14, 2024 1:25 pm
Forum: Valves
Topic: Valve amplifier service
Replies: 200
Views: 100142

Re: Valve amplifier service

Or £1.31 if you just need something simple. https://www.switchelectronics.co.uk/products/ne555-adjustable-duty-cycle-pulse-frequency-square-wave-signal-generator-module-1?variant=45334951264565&currency=GBP&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_cam...
by Nick
Tue May 14, 2024 9:10 am
Forum: Valves
Topic: Valve amplifier service
Replies: 200
Views: 100142

Re: Valve amplifier service

Dave reports the amp sounds "wonderful" and has been stable so far. Phew! I cant help thinking that if such a radical change in the level of feedback has not broken the amp (in one or another way) then the original value was in fact wrong. Did you check the original value to make sure the...
by Nick
Tue May 14, 2024 9:06 am
Forum: Valves
Topic: Valve amplifier service
Replies: 200
Views: 100142

Re: Valve amplifier service

Yes, exactly that.
by Nick
Tue May 14, 2024 9:04 am
Forum: Speakers
Topic: TG "The Loudspeaker" Build (Sort of)
Replies: 180
Views: 19266

Re: TG "The Loudspeaker" Build (Sort of)

Yes very interesting. I can't help thinking that getting an adequately balanced platter, with suitable thickness, roundness and centrality would be exceptionally difficult for DIYers though. Unless I missed something, that why I said plinth. I was thinking of what the l07-d was made like "The ...