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Search: Posts Made By: Richard
Forum: Problems 19th January 2020, 01:23 AM
Replies: 3
Views: 101
Posted By Richard
Re: WD88XL switch off hiss

Hi Alasdair,
Firstly, could it be any pre-amp or source connected that is doing this? If any are connected turn them off first of course.
Then you could try to locate the area of the problem by...
Forum: WD Amplifiers 19th January 2020, 01:13 AM
Replies: 8
Views: 178
Posted By Richard
Re: K5881 Mk1 mods

Hi, yes if you're not hearing any distortion or getting motorboating all should be well. Great car, I bet that took longer to build than the 5881! Best film I saw last year was Ford vs Ferrari, I...
Forum: WD Amplifiers 16th January 2020, 11:58 PM
Replies: 8
Views: 178
Posted By Richard
Re: K5881 Mk1 mods

Hi Phil and welcome, do you have a Dax Cobra? I digress :) but mostly agree with Greg and Phil and would say,

1) the input cap will block DC from a source but that's unlikely to be needed as the...
Forum: WD Amplifiers 12th January 2020, 05:19 PM
Replies: 23
Views: 559
Posted By Richard
Re: Any suggestions re; KiT6550 brightness?

Happy New Year everyone!
Yes I'd change the coupling caps. Vishay axial polyesters are natural sounding, google RS 185-4369...
Forum: The Coffee Bar 29th December 2019, 03:31 PM
Replies: 11
Views: 296
Posted By Richard
Re: New forum member

The valves should be good then but they run at max dissipation so keep and eye on the plates in a dark room for any red patches.

If the pcb comes out again consider increasing the first valve...
Forum: The Coffee Bar 29th December 2019, 12:32 PM
Replies: 11
Views: 296
Posted By Richard
Re: New forum member

Hi Merlin and welcome to the madhouse.

These were launched in Nov 1999 and based on the well liked Kel34. All paper-work is available, send me a message if you need it.

Hum can be simply a...
Forum: The Coffee Bar 24th December 2019, 01:12 PM
Replies: 10
Views: 283
Posted By Richard
Happy Christmas everyone!

Wishing everyone a Happy Christmas and a good New Year!
Forum: Problems 21st December 2019, 06:36 PM
Replies: 22
Views: 637
Posted By Richard
Re: PSU III transformer information.

Hi Philip, yes reading some more, the LM317 divider will also be part of the load. Using 240R at R1 results in 5mA or using 120R at R1 results in 10mA. Phono 3 uses 4.2mA.

LM317 TI data sheet...
Forum: WAD General 20th December 2019, 05:48 PM
Replies: 2
Views: 176
Posted By Richard
Re: KiT/KaT6550 Power consumption.

Excellent Neil, no haven't tried it and don't have a smart meter, but that looks accurate as the amp has a 1.6A fuse fitted and occasionally blows it at switch-on so I figured something over an amp...
Forum: Problems 19th December 2019, 01:59 PM
Replies: 22
Views: 637
Posted By Richard
Re: PSU III transformer information.

Hi Bob, I know little about these but a look at the data sheet suggests a minimum 10mA load. The web design may be good but I wonder if the tiny 4 or 5mA load of Phono is enough? I may be reading the...
Forum: Problems 18th December 2019, 10:29 AM
Replies: 22
Views: 637
Posted By Richard
Re: PSU III transformer information.

Morning Bob, thanks for the explanation and hope the new one is easier to implement. What regulator arrangement are you using?
Forum: WAD General 18th December 2019, 10:28 AM
Replies: 15
Views: 750
Posted By Richard
Re: WAD 300B PP Rebuild Advice Needed.

Good luck and let us know how it goes Zak. Valve amps are inherently untidy and personally I'd just go for a tidy-up :thumbsup:
Forum: Problems 16th December 2019, 10:58 PM
Replies: 22
Views: 637
Posted By Richard
Re: PSU III transformer information.

Doesn't that just indicate it's a higher voltage TX Bob? Did Tiger tell you the specs for that part number?
Forum: Problems 16th December 2019, 08:23 PM
Replies: 22
Views: 637
Posted By Richard
Re: PSU III transformer information.

Surely the draw for Phono is tiny so we could just drop it after the rect and before the caps at R1?
Forum: Problems 16th December 2019, 02:19 PM
Replies: 22
Views: 637
Posted By Richard
Re: PSU III transformer information.

Put the dropper at R1 before the caps rather than R6 after?
Forum: WAD General 16th December 2019, 02:08 PM
Replies: 15
Views: 750
Posted By Richard
Re: WAD 300B PP Rebuild Advice Needed.

Hi Greg, and All,
I didn't cut the pcb track, just disconnected the pcb ground from the 300B ground, then wired the neg legs of the C5 caps to the ground splodge as you may be able to see by the...
Forum: Problems 16th December 2019, 01:49 PM
Replies: 22
Views: 637
Posted By Richard
Re: PSU III transformer information.

Hi Bob, that's good, do you need a new TX?
I don't know what reg you're using but if you set it up again as a passive supply can you then find a dropper R to leave just enough over-voltage (280V to...
Forum: Problems 16th December 2019, 10:34 AM
Replies: 22
Views: 637
Posted By Richard
Re: PSU III transformer information.

Hi Bob, maybe Dave C had some for evaluation. How did you end up with it, a kit or parts from when Peter left? Tiger has contact details here so maybe drop them an email for the spec,...
Forum: WAD General 14th December 2019, 01:50 PM
Replies: 15
Views: 750
Posted By Richard
Re: WAD 300B PP Rebuild Advice Needed.

Hi Zak, that looks a good plan.

Mine came with DC heaters for the small valve(s?) which I kept so I don't know about the original AC heaters.

I found a couple of pics of the original and...
Forum: Problems 13th December 2019, 07:21 PM
Replies: 5
Views: 218
Posted By Richard
Re: Loud squeal from speakers - KEL84

Hi Darran, that's great news, thanks for letting us know :thumbsup:

The ECF80 first stage is a high gain pentode which is capable of very high frequency amplification and can be susceptible to...
Forum: WAD General 12th December 2019, 06:55 PM
Replies: 15
Views: 750
Posted By Richard
Re: WAD 300B PP Rebuild Advice Needed.

Hi Zak and John,

Yes I used EH valves too and think you should have no problem reverting the amp to standard with just the cathode R change. Mine was second-hand and came with a few mods which I...
Forum: WAD General 11th December 2019, 10:32 AM
Replies: 15
Views: 750
Posted By Richard
Re: WAD 300B PP Rebuild Advice Needed.

Hi Zak,

Well, the 820R resistors will drop the HT.

The HT is 565V nominal and as standard each pair of 300Bs draws 160mA so they'll drop approx 130V (= 21W) each. There'll be some...
Forum: WAD General 10th December 2019, 10:06 AM
Replies: 15
Views: 750
Posted By Richard
Re: WAD 300B PP Rebuild Advice Needed.

Hi Zak, Rather than us trying to second-guess it might be better to ask the chap who sold you the amp :thumbsup:
Forum: Problems 8th December 2019, 08:37 PM
Replies: 5
Views: 218
Posted By Richard
Re: Loud squeal from speakers - KEL84

Hi Darran, yes the ECF80 each have 2 valves inside the glass envelope. The first is a high gain pentode section to increase the signal coming in and the second is a triode section arranged as a...
Forum: Problems 8th December 2019, 05:58 PM
Replies: 5
Views: 218
Posted By Richard
Re: Loud squeal from speakers - KEL84

Sounds like a feedback problem or faulty valve.
Check for accidental plugging or selecting a wrong input.
Is it both channels?
I'd remove, clean and refit the valves and try other ECF80s if you...
Showing results 1 to 25 of 4771

 
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