Tannoy Reveal 6D

[danielrussu]

Re: Tannoy Reveal 6D

Dear midibob,
It seems you are my one and only hope. I face similar troubles with the nasty 6D amp and I desperately need its schematics. I'll be most grateful to receive them from you and mostly happy to help with anything.
Regards,
Daniel
daniel_r@israelmail.com

[midibob]

Re: Tannoy Reveal 6D

Hi Daniel,
I've PM'd you. I did mail them but you obviously haven't received them?

Bob

[budm]

Re: Tannoy Reveal 6D

Remove the brown glue right away and see if it had eaten away any copper traces and leads, very common problem from long time ago. It is conductive and corrosive. Fixed many consumer products due to damage by glue, also cause intermittent problem and unstable circuits due to conductive issue, especially in the audio circuits and power supply

[Unaspected]

Re: Tannoy Reveal 6D

If anyone has the schematic, could they PM me? Tried to access your profile to send a message, Midibob but was denied - presumably because this is my first post - so I'll try again after this post.

Fixing these Tannoys or finding a quick replacement is of great importance.

It's that or invest in a pair of Adams...

...would rather save money than spend.

[midibob]

Re: Tannoy Reveal 6D

Hi,

Could be a 'first post' thing, I don't know? I'll drop you a PM and see what happens.
I see you are in Surrey so we are probably not too far away from each other.

Midibob

[SteroidSounds]

Re: Tannoy Reveal 6D

Hello.
One more for the schematic.
midibob would you be kind enough to send it?

Thanks in advance

[islou]

Re: Tannoy Reveal 6D

My issues turned out to be the volume pot, followed the signal around the schematic till i tracked it down.

I usually run them at half volume so for the time being i removed the pot, measured it at half volume (since its a log pot) and replaced it with high tolerance resistors.

They have been working a treat ever since! Sound a bit more confident too, i think the pot was right on the edge even when it was working. Also removed the brown glue gunk as midibob suggested too.

The strangest part is that they now seem to run cooler, any ideas as to why this might be ?

[Scenic]

Re: Tannoy Reveal 6D

http://pixelbanane.de/yafu/350940276...schematics.zip
http://91.121.194.115/tannoyschematics.zip
Same file, just mirrored..

[SteroidSounds]

Re: Tannoy Reveal 6D

Thank you Scenic.
I'll post back when speaker is repaired.

[danielrussu]

Re: Tannoy Reveal 6D

I'll detail my case for the benefit of the forum. It's about a pair which broke almost together. The most likely reason: they were half mounted inside a decorative cabinet which obviously clogged natural cooling.
The first unit exhibited severe distortion together with visible random shifting of the driver diaphragm. First inspection denoted burning of IC4 stabilizer, but the very problem was the “mute“ circuit around T1 that I replaced together with almost all of the electrolytic cap's which dried up: C1, C6, C18, C21, C11, C12, C22, C23. It's better to check them all. Also they should be 105°C.
The second unit was completely mute. During checks the BR1 bridge proved broken, but it might have occurred consequently. The main problem was still in the “mute” circuit, this time the D15 Zener which didn't behave. A number of capacitors from the above list were also replaced.
It's worth to check the voltage on pin 8 (the “mute”) of LM3886. In normal working (and ampli ON state) it should be some -20V.
A couple of words about dismantling the power module of the Reveal – a real nightmare. The main screws retaining the module in place are – of course, how else – behind the massive heatsink (they fasten the two IC amps against the main aluminum plate by means of a strip). In other words one has to remove the heatsink in order to reach these screws.
Do you think it's simple? You make me laugh. In order to remove the heatsink you have to remove the…power transformer since one screw is exactly underneath. Do you think removing the transformer is simple? Don't remind me…
Be careful with all the cables that came in touch with the damned varnish: their PVC insulation got stiffened and frail. They will break at once.
Not to mention other little troubles as, for instance: the plastic body of the RCA plugs dried up and crumbled such that their retaining screws got useless.
Shortly this was not an easy and pleasant work to accomplish.
Many thanks again to midibob for the schematics.

[midibob]

Re: Tannoy Reveal 6D

A good thorough diagnostic and repair which should aid others.

It's a shame that there appears to be built in obsolescence, mind you doesn't most stuff made in China these days.

I know what you mean about the screw removal, it is a pain. For future repairers be careful not to round off the crosshead screws with a badly fitting screwdriver, otherwise you'll never get them off.

Still looking for the specific 120 Ohm 5W resistors in the UK????

Midibob

[mtausch11]

Re: Tannoy Reveal 6D

I had the same problem with my Tannoy 6d's. They would cut off then I would jiggle some of the switches on the back of the monitor's and they would work again. Eventually they stopped working all together. I'm not the most technically gifted with electronics so I'm not sure what to do. I took the back off of one of the monitors (only slightly damaging the case with a screwdriver) and saw everything was covered in glue like a 5yr. old put it together. I tried cleaning some of it off but there is so much of it and I didn't want to ruin it.
The only way I have to test the sound at this moment in time is through the spdif input which on the one I cleaned up gives a very soft sound from the tweeter and that's it. The other one gives me nothing.
What do you recommend?
Thanks,
Matt

[midibob]

Re: Tannoy Reveal 6D

Hi Matt,

If you follow some of the previous posts I would definitely start with removing any of that glue, that has gone hard, from the circuit boards. This can cause all sorts of bizarre problems due to conductivity. Even if it doesn't cure anything at least you've eliminated one possible problem.

I didn't have any success trying to clean the switches so replacements might be the only proper repair for those if they don't respond to flicking up and down a few times. After that it's really down to checking voltages and tracing the signal path.

Good luck
Midibob

[mtausch11]

Re: Tannoy Reveal 6D

Hey Midibob,

Thanks for the advice. Next question, how do you recommend removing the glue. I looked online and they mentioned rubbing alcohol which isn't working too well. I initially tried scraping but didn't want to ruin the board. Any ideas?

[midibob]

Re: Tannoy Reveal 6D

As you have probably seen from my earlier posts it's a real swine to remove. The best method I found was to use a plastic scraper. If you attack it at the edges it more often than not lifts it off the board in big pieces. I would be careful using some solvents though in case they attack other plastics. IPA is OK but it is really only good for cleaning up afterwards.
I did try flux remover which I think is more of a carbon tet solvent but that only had a negligible effect on it.

Mind you this is for the stuff that's already gone hard, for the soft stuff it's really down to using your fingernails.

Why they couldn't have used proper silicone I don't know?

Midibob

[mtausch11]

Re: Tannoy Reveal 6D

Thanks again for the input!!!

Much appreciated

[borjam]

Re: Tannoy Reveal 6D

I use a pair of Reveal 6Ds, and one of them was developing a fault lately, after being powered up for some time, and getting hot, the volume would decrease a lot.

Turns out it was the bloody gunk below the resistors. And, luckily, there was no other damage yet. Just cleaning carefully has done the trick.

I'll proceed to clean up the gunk in the other speaker before it develops a problem...

Thank you for the really useful tip

[mtausch11]

Re: Tannoy Reveal 6D

Ok, so I removed as much of the glue as I could without scratching up the circuit board too bad. I plugged in the monitors and the tweeters were working. That's a start. Took them apart again and one of the connections that go to the speakers was making sounds when I was moving it. (yes I had them playing with my hands back there) I unplugged the faulty connection and put it back in and wallah!!!!! It Works!!!!!!!!!!!!!!!

Thanks MidiBob!!!!! One down one to go. It really is a pain in the ass though.

[borjam]

Re: Tannoy Reveal 6D

Midibob, if you happen to come to Bilbao (Spain) and you like jazz, let me know

[midibob]

Re: Tannoy Reveal 6D

Muchas gracias.

I'm sure the weather out there is a lot better than London, especially this year.

I'm glad the tips were of use.

Midibob