WD KT88 Front Panel and Power Switch

[Radioham]

Hi,
I have just purchased a used WD KT88 and I am very pleased with its performance.

I noticed that the front panel is engraved with text, however its quite hard to see. Should the engraving be filled in with something ? If yes what do you suggest ?

Also when I turn he amplifier off I notice a bit of buzzing from the speakers, do you think the switch is failing, or perhaps needs a mains rated capacitor across the contacts ?

On a more general note, I have spent many hours with my local dealer evaluating amplifiers up to the price point of £7K and the WD beats them all , the main reason being sensible input sensitivity (440mV) , decent analogue volume control and very good sound.

Kind Regards
Alan

[bob orbell]

The front panel engraving is as supplied, you could if you wish wipe paint into it but this will take time, the buzzing on switch off is the HT capacitors discharging and is only audible if your music source is still playing, with no music playing there should be almost no sound at switch off. Bob

[Richard]

Hi Alan and welcome. Great to hear you like the amp.

Thoughts on the switching noise are,

To check if it's the switch I'd try switching it off at the wall switch or pulling the plug there to see if it still makes a noise powering down.

If yours has the switch combined with the mains inlet it may be worth a squirt of Servisol otherwise fit a new one.

They do switch quite a high load and a CR series network across LN on the load side wouldn't hurt and may prolong the switch life. I've had experience of these on Quad amps and made up networks ro replace the standard Rifa units which do not last very long for some reason. With the ones shown in attached pic fitted there is no switch-off noise at all. (A small thump as the amp is powered up is usual as it stabilises.)

[Radioham]

Hi Many thanks for all the info. I was aware of the Quad amplifier so may make up a similar CR network. I will try the power down tonight without using the switch. Yes the switch is combined with the IEC socket.

Alan

[bikerhifinut]

Hi.
I agree with Bob and Richard.
It's a very nice amp, and if it's been assembled with care and attention to detail should prove highly reliable.
I won't delve into the dark area of component technology and the various perceived effects on the performance, you'll get a different answer off everyone I feel.
I modded mine from a single input to the integrated version when I scored a bargain front panel. I used the relay board from Matthew at WD and with a few caveats on being VERY careful when assembling it, I think its been worth it although if you've got good DIY skills its just about possible to shoehorn your own relay board at the rear if you feel sufficiently masochistic! I made an assumption there that you perhaps have the single input version.
The other mod I made and one that I felt was well worth it was to fit a remote control motorised Volume pot.
I used the Hi Fi Collective board which although very expensive for what it is, does work very well and with a bit of ingenuity on the mute relay switch I also got the mute function to work by putting it in the supply line to the source relays off the selector switch. works a treat and not on the signal path.
I put the sensor where the indicator LED on the front panel sits, frankly I feel the power LED is a decoration, its easy enough to see if the heaters are lit up and if the HT failed the amp wouldnt work anyway. I will have to look under the cover as i think I managed to mount the board in such a way that I didnt have to demount the IR sensor off the PCB. I used a standard ALPS "Blue" RK127 pot. Bob passed it on to me but they are available from WD or RS for a bit less, worth it if you're putting in a big eough order for free postage, otherwise......... It's a tight squeeze but it will clear the KT88 valve bases with sufficient space. I used a standard Rega remote control as the HFC board uses the Philips RC5 code, some Arcam and Marantz ones will also do the job.
Anyway it works a treat and makes all the difference.
I prefer the WD88 as an integrated rather than use it with a preamp of any sort, given that I use it close to my source units and so the connecting leads are quite short.
Others prefer a preamp, again its personal preference here I feel.
all the best and 73's

Andy.

[Radioham]

Originally Posted by bob orbell

The front panel engraving is as supplied, you could if you wish wipe paint into it but this will take time, the buzzing on switch off is the HT capacitors discharging and is only audible if your music source is still playing, with no music playing there should be almost no sound at switch off. Bob

I did have the audio source still running (TV sound from Tivo Box) but now put the amplifier into mute and switch off is now silent.

BTW I believe the amplifier was supplied ready built by WD and not home brew since I would be concerned about build quality and safety issue.

Alan

[BOONDI]

A lot of kit builds by the guys on here come with a quality of build equal to or better than factory. And thats saying something. I hope because you have a well built amp that it will give you sterling service. An easy way to get your lettering to stand out is to use a bit of black gloss on the lettering and the a quick wipe with cloth then a second wipe with a cloth with a bit of turps. Not dripping, just damp enough to remove the gloss from the surface. Try to fold the cloth into a square the same width as the panel. Don't press to hard, just a quick wipe from one side to the other. Then when it's clean, leave it to dry.....