Search found 4048 matches

by Andrew
Sat Aug 04, 2018 8:49 am
Forum: Valves
Topic: Finished and working - 12 valve all DHT PP 26-71a-45
Replies: 33
Views: 520

Re: Finished and working - 12 valve all DHT PP 26-71a-45

Yep, agreed, Nick, "shorting out" is a better description.
by Andrew
Fri Aug 03, 2018 9:42 am
Forum: Valves
Topic: Finished and working - 12 valve all DHT PP 26-71a-45
Replies: 33
Views: 520

Re: Finished and working - 12 valve all DHT PP 26-71a-45

If you can get that cap away from the DHT heater, it will sound even better. The cap is a voltage source and will be attempting to "regulate" the music signal on the DHT's heater.

Will the boards you bought not do the job?

Great job, by the way!

Andrew
by Andrew
Thu Aug 02, 2018 5:08 pm
Forum: Valves
Topic: Finished and working - 12 valve all DHT PP 26-71a-45
Replies: 33
Views: 520

Re: Finished and working - 12 valve all DHT PP 26-71a-45

Where are the caps on the 45 heaters? Is is CLC?

cheers,

Andrew
by Andrew
Tue Jul 03, 2018 4:12 pm
Forum: Everyones Projects
Topic: Adventures in LCR Phonos
Replies: 16
Views: 396

Re: Adventures in LCR Phonos

I would ditch the grid leak bias, that big resistor is a potential source of hum noise, and as the 88 ages it may runaway, especially if you replace the 88 with something with more GM, like D3A. By all means try it as is, but be prepared to chase hum. This is one of those times when a bigger cap and...
by Andrew
Tue Jul 03, 2018 7:33 am
Forum: Assorted Stuff
Topic: Next Owston meet 30 june/1 July 2018
Replies: 174
Views: 7045

Re: Next Owston meet 30 june/1 July 2018

IslandPink wrote:
Mon Jul 02, 2018 8:40 am
I'll meet you half-way : it was two tracks, ie. one LP !
It was plenty ;)

Thanks to Steve for organizing, great to see everyone again.

Andrew
by Andrew
Tue Jul 03, 2018 7:31 am
Forum: Everyones Projects
Topic: DHT Heater using VCCS - PCB or Kit (Possible Group buy)
Replies: 1014
Views: 72438

Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Hi Mick,

I wont' ask what happened. You really need Panasonic FR Series, high ripple, not cheap but worth it.

cheers,


Andrew
by Andrew
Thu Jun 14, 2018 7:51 pm
Forum: Everyones Projects
Topic: DHT Heater using VCCS - PCB or Kit (Possible Group buy)
Replies: 1014
Views: 72438

Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Those remaining are:

Neal : 4 x large
Michael L 2 x large

Neal are you planning on being at Owston?

thanks,

Andrew
by Andrew
Tue Jun 12, 2018 9:35 am
Forum: Everyones Projects
Topic: DHT Heater using VCCS - PCB or Kit (Possible Group buy)
Replies: 1014
Views: 72438

Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

IslandPink wrote:
Tue Jun 12, 2018 8:32 am
Thanks - another 8 would be handy for two more boards. Will you be at Owston ?
Planning to be there.

Andrew
by Andrew
Tue Jun 12, 2018 7:52 am
Forum: Everyones Projects
Topic: DHT Heater using VCCS - PCB or Kit (Possible Group buy)
Replies: 1014
Views: 72438

Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Mark, I've got a also got few spares, if you need them.

Andrew
by Andrew
Tue Jun 05, 2018 7:13 am
Forum: Everyones Projects
Topic: DHT Heater using VCCS - PCB or Kit (Possible Group buy)
Replies: 1014
Views: 72438

Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Hi Mark,

Yes, it's a SK129, select preferred height depending upon required degs/watt and ambient temp.

cheers,

Andrew
by Andrew
Mon Jun 04, 2018 7:58 am
Forum: Everyones Projects
Topic: DHT Heater using VCCS - PCB or Kit (Possible Group buy)
Replies: 1014
Views: 72438

Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

Hi Mark, Non epoxy caps, not taking that risk again ;) http://uk.farnell.com/kemet/c2220c474j5gactu/cap-mlcc-c0g-np0-470nf-50v-2220/dp/1679460?ost=1679460&ddkey=http%3Aen-GB%2FElement14_United_Kingdom%2Fsearch Pretty much any green LED, I use the HLMP Y502, data sheet can be found here http://uk.far...
by Andrew
Thu May 31, 2018 7:56 am
Forum: Everyones Projects
Topic: DHT Heater using VCCS - PCB or Kit (Possible Group buy)
Replies: 1014
Views: 72438

Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

I've heard from Mick, anyone else care to choose Owston or the Royal Mail?

best regards,

Andrew
by Andrew
Tue May 29, 2018 8:30 pm
Forum: Stacks
Topic: DHT Heater Group Buy notes.
Replies: 25
Views: 3609

Re: DHT Heater Group Buy notes.

Multimeter measures 115mV AC at the simulated filament (resistor). What's normal? Might be better scoping it. 115mv :shock: that's huge, are you certain it's all ok? The AC component should be tiny, like less than 2mV (from memory) please have look at the FFT graph/imagess in the group buy for refe...
by Andrew
Tue May 29, 2018 8:24 pm
Forum: Everyones Projects
Topic: DHT Heater using VCCS - PCB or Kit (Possible Group buy)
Replies: 1014
Views: 72438

Re: DHT Heater using VCCS - PCB or Kit (Possible Group buy)

I received a delivery of back ordered parts today so I can start shipping again, I'm still short the 1K Carbons for just two remaining boards and will go hunting for those. I owe..... Mick : 2 x large Thomas: 4 x large Neal : 4 x large davedms: 2 x large Michael L 2 x large For those going to Owston...