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Search: Posts Made By: John Caswell
Forum: WD Amplifiers 26th June 2018, 08:36 AM
Replies: 7
Views: 186
Posted By John Caswell
Re: WAD CF Pre relayboard not working Help

Hi Colin et al,
Although I am not normally into violence I have to admit a good slap often helps gel the brain:D
Nicely done Colin

John
Forum: WD Amplifiers 25th June 2018, 05:41 PM
Replies: 7
Views: 186
Posted By John Caswell
Re: WAD CF Pre relayboard not working Help

Hi Colin,
1) Did it work originally?
2) Is the 6.3 v supply the correct way round, because the LED is not lit up, which could mean that the heaters supply is the wrong way round.

John
Forum: WAD Problems 16th June 2018, 11:19 PM
Replies: 2
Views: 117
Posted By John Caswell
Re: KiT/KaT6550 and fuse blowing inrush current

Hi Greg,
Yes this item is fine and as Farnell says a suitable replacement for the original.
Just remember to mount it on longish leads as it gets pretty hot and contrary to my general...
Forum: WD Amplifiers 7th May 2018, 10:09 AM
Replies: 5
Views: 266
Posted By John Caswell
Re: Converting WD KT88 to XLR

Converting the WD88 to balanced inputs is a relatively simple job.
There are two ways of doing it either electronically using a dedicated unbalanced to balanced IC, or using a 1:1 transformer...
Forum: The Coffee Bar 6th May 2018, 03:58 PM
Replies: 32
Views: 984
Posted By John Caswell
Re: SME & Garrard

Baggy,
Don't worry about it.

John
Forum: The Coffee Bar 5th May 2018, 10:48 AM
Replies: 32
Views: 984
Posted By John Caswell
Re: SME & Garrard

Gentlemen,
Don't let this thread degenerate into a polite but nevertheless "slanging match" re belt/idler/direct drive turntables. I has all been done to death elsewhere. Everyone has their own...
Forum: Amplifiers 3rd May 2018, 10:34 PM
Replies: 3
Views: 315
Posted By John Caswell
Re: 5881 Amp building instructions

Hi Snodge,
There were some layouts in the supplements, which I will have a look for, but I suggest that you try Matthew at World Designs first.
Bear in mind that there were three variations on a...
Forum: WAD General 15th April 2018, 09:12 AM
Replies: 8
Views: 399
Posted By John Caswell
Re: Kat6550 vibration/hum

Hi all,
The 6550 was a WAD design and as such had steel chassis, so of course things are a bit different.
A bolt to stress the base between the top of the chassis and the base may help or even some...
Forum: WAD General 1st April 2018, 01:04 PM
Replies: 8
Views: 473
Posted By John Caswell
Re: Kat88 Power Amp Seen On Sale

Hi all,
The Sowter 082 was not so much an upgrade as a change as I was not very happy with the original output transformer which exhibited some nasties. The later opts were much improved.

John
Forum: WAD General 31st March 2018, 02:22 PM
Replies: 8
Views: 473
Posted By John Caswell
Re: Kat88 Power Amp Seen On Sale

What output transformer upgrade???????

John
Forum: WD Amplifiers 30th March 2018, 04:59 PM
Replies: 47
Views: 1,757
Posted By John Caswell
Re: KEL84XL build

Hi all,
Hum can be the very devil to sort out. This is interesting in that with all inputs removed there is no hum but with inputs from the Schiit (unfortunate name that!) there is hum.
I have had...
Forum: The Coffee Bar 19th March 2018, 11:28 PM
Replies: 4
Views: 349
Posted By John Caswell
Re: BBC scraps plans to turn off FM

I breathed a sigh of relief reading this, but the question one must ask is, is everything analogue going to be digitised then re analogued (bad english!!) at the transmitter, with all the associated...
Forum: Problems 2nd March 2018, 05:01 PM
Replies: 22
Views: 1,093
Posted By John Caswell
Re: Phono3S it's humming again.

Hi Andy,
Yes exactly that, I keep the belt on the small 33 rpm pulley, otherwise the voltage required for 33rpm on the large pulley is quite low.
Use something like a 9-12V 15VA toroid and an...
Forum: Problems 2nd March 2018, 09:28 AM
Replies: 22
Views: 1,093
Posted By John Caswell
Re: Phono3S it's humming again.

Hi Andy,
Placing a die cast case around the Gyro PSU will not help as it is an electromagnetic field the is causing the problem. Only mumetal or distance will help and that is a seriously expensive...
Forum: Problems 1st March 2018, 02:19 PM
Replies: 22
Views: 1,093
Posted By John Caswell
Re: Phono3S it's humming again.

Andy, with all inputs removed does it still hum? If so try putting phono plugs with 100R soldered across them on input sockets to see if it still hums. If so, you need to look at the phono stage, if...
Forum: General 25th February 2018, 06:36 PM
Replies: 9
Views: 477
Posted By John Caswell
Re: A naive, possible, safety idea

Hi all,
Having spent a good few years building /fixing all sorts of electronic equipment here is my two penn'orth.
The sort of voltages that we deal with on this forum are dangerous, but that...
Forum: General 31st January 2018, 08:34 PM
Replies: 20
Views: 993
Posted By John Caswell
Re: help tapping screw threads

Hi all,
I believe the TORX head was developed in the US by Camcar Textron and that is as as far as my knowledge goes. Suppose I should look it up in Wiki:D

John
Forum: General 31st January 2018, 09:05 AM
Replies: 20
Views: 993
Posted By John Caswell
Re: help tapping screw threads

Hi all,
JohnG's and Bob's comments are very relevant, the original Philips head screws used to suffer from "cam out" due to their sloping sides, and very often worn screwdrivers. "Pozidriv" heads...
Forum: WD Amplifiers 25th January 2018, 09:04 AM
Replies: 3
Views: 420
Posted By John Caswell
Re: that 2 colour LED on KT88

Hi Andy,
First of all ideally you require a matched pair of KT88, if not you could strike hum/distortion problems.
Yes you could certainly fit an LED to each KT88 cathode/heater, but personally I...
Forum: Problems 16th January 2018, 05:41 PM
Replies: 7
Views: 584
Posted By John Caswell
Re: Help needed Kit 88

Hi K,
I assume that this is a WAD Kit/Kat88 and not a WD 88VA but the same rules apply either way.
If the amplifier is an integrated version with a tape output then you can use this to feed the sub...
Forum: WAD General 5th January 2018, 03:36 PM
Replies: 15
Views: 800
Posted By John Caswell
Re: Rarely Seen WAD, Andy Groves Designed, IC Phonostage

Got one of these, and very good it is too.
The way it was designed AG changed the ICs around MM to MC so it may not be easily possible to make it dual standard, but by all means have a look and see....
Forum: General 5th January 2018, 03:33 PM
Replies: 5
Views: 463
Posted By John Caswell
Re: 6N5P/6AS7/6080 any ideas?

The 6AS7/6080 is, as Richard says, a heavy duty double triode initially designed as a series regulator but like so many others (6C33CB) have found use as an output valve.
They are pretty well bomb...
Forum: WD Other Parts and Projects 5th January 2018, 03:28 PM
Replies: 4
Views: 772
Posted By John Caswell
Re: WAD Kit 6550 hum

Why do you need new transformers??
Please explain.

John
Forum: General 24th December 2017, 04:28 PM
Replies: 8
Views: 479
Posted By John Caswell
Re: X class cap

Hi all,
As I said Sod's law will always apply:D

John
Forum: The Coffee Bar 24th December 2017, 12:46 PM
Replies: 24
Views: 1,336
Posted By John Caswell
Re: The down side off getting old.

Hi Bob,
Just curious, is the tensile strength of SS adequate for your applications?

John
Showing results 1 to 25 of 1432

 
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