Tannoy Reveal 6D

[tjc]

Re: Tannoy Reveal 6D

Hah, yes, I did that for a while and it worked. But something on the board failed again and I ended up elbow-deep in the project. I might be slow but I do occasionally surprise myself and finish projects!

[Khron]

Re: Tannoy Reveal 6D

Or perhaps a better(?) idea would be to solder wires to where the resistor would be mounted, and mount the resistor itself off the board, in some more remore area, where it can "breathe" AND not burn anything else...

[tjc]

Re: Tannoy Reveal 6D

A few things finally left the bench and I had some time to work on this. I've documented it a bit more on my webpage:

http://www.cs.wisc.edu/~timc/e/tannoy.html

To summarize, L1, the 120ohm 5W resistor smoked my amp board a few years ago so I etched another one last week. I populated the board, tested the voltages, installed it. No good -- L1 gets stinking hot, 190F/88C, quickly.

Next things on my list are to disconnect the digital board -- we'll see if it's there. If not, it's the input board I suppose. In any case, lots of brown goop to clean up.

BTW, the output from C19 and C20 are around +/-40VDC.

[midibob]

Re: Tannoy Reveal 6D

Looks like you're almost there. I can't remember now when L1 failed on mine whether it was down to one of the ic's on the other boards. I'm sure it won't take you long to find it.

Interesting that you're using the toner transfer method, I'm in the process of doing something similar here. Single sided is easy, double sided is a pain in the backside!

Midibob

[Th3_uN1Qu3]

Re: Tannoy Reveal 6D

I got near-perfect results with toner transfer, if i take my time to iron the board properly. I've done 10 mil (0.25mm) traces with no issues. I've yet to do my first double-sided board however, but it's soon to come.

[tjc]

Re: Tannoy Reveal 6D

The lack of instant gratification was a little let-down but I'm looking forward to finding the actual fault now.

I think the toner transfer method would work better for me if I started with better tools. My first pass with high-clay content magazine paper (has worked for me in the past) was a complete dud, no toner stuck to the board. Clean up, try again. Attempt number two with PSA label paper, labels removed, worked OK but under 10x magnification I noticed thin lines of missing toner where the original labels were die cut. Out came the sharpie.

I should just buy some commercial toner transfer paper for next time.

The 2-sided process wasn't bad. I pre-drilled three registration holes in certain traces that easily located the front with the back. That got me close enough. The worst registration error is by about 2mm in one spot and I can't say that isn't completely due to my ham-handed retracing of the board on the computer.

[tjc]

Re: Tannoy Reveal 6D

Success, I guess?

The speaker is once again sounding good and could potentially be put back into service. I made some updates to my webpage with some other foibles along the way.

A few numbers: the audio input board pulls ~58mA on both the + and - lines.

The 220 ohm resistor before the LM7915 has about a 14V drop -- 39.5V to 25.5V and dissipates almost 1W. I'm using a 5W axial resistor for this and it's getting too hot for my liking.

The 120 ohm resistor before the LM7815 has about a 7.3V drop -- 39.5V to 32.2V and dissipates ~0.4W. Warms up, doesn't get too hot.

I think I'm going to go with one of the suggestions above and replace both resistors with chassis-mount power resistors attached near (not taking the whole thing apart again!) the heatsink on both this and the speaker that hasn't yet had a problem. I think the resistors are fine dissipating that amount of power but there's nowhere for the heat to go in that enclosed space.

Thanks all the way around for the info, schematics and prompting to get this project back on the bench and fixed!

[Bagger]

Re: Tannoy Reveal 6D

Hi guys, this is my first real post here. Could you be so kind and refresh the Reveal 6D schematic please? The old links don't function.. My problem is buzzing sound from one of the speakers so the first tip are the resistors. Your help would be much appreciated.

[midibob]

Re: Tannoy Reveal 6D

The mirrored link works for me OK?
If you can't get it to work drop me a PM with your mail address and I'll send them across.

Midibob

[rbilliex]

Re: Tannoy Reveal 6D

I could use a schematic for these monitors also. Anyone?

[midibob]

Re: Tannoy Reveal 6D

Try the mirrored link a couple of pages back in the thread.

http://91.121.194.115/tannoyschematics.zip

Midibob

[Don Stewart]

Re: Tannoy Reveal 6D

Midibob,

I realise its been a couple of years since this thread was active but I wonder if you might still have the schematics handy for the Tannoy Reveal 6D speakers.

I have just repaired a 66D which had a problem with the mute circuit and although it is now working I would really like to see the circuit diagram just to confirm my analysis of the fault and make sure my repair mod won't cause any more problems down the line.

Cheers,
Don.

I've just found the links to the zip file with the schematics

[midibob]

Re: Tannoy Reveal 6D

Hi Don,

Glad you've got them OK. It's always good to have a look at the diagrams.
Well done for fixing it, why don't you let everyone know what you did as I'm sure there will be lots of interest.

[Mobidik]

Re: Tannoy Reveal 6D

Hi guys, hi MidiBob. Of course, I'm just the one more desperate 6D"s owner with common problems. I decided to make the pcb's from a scratch and Midibob if u can share your pcb files it will be very helpfull. At last it will save me some time possible? Thanks

[midibob]

Re: Tannoy Reveal 6D

It wasn't me that made the PCB so I don't have any PCB layout info. See a few posts back for the link to the guy who made his own.

http://www.cs.wisc.edu/~timc/e/tannoy.html

Cheers

[Mobidik]

Re: Tannoy Reveal 6D

Oops, Sorry Midibob. I was blind after few hours of removing black ugly thing from6D pcb's I still cant believe that Tannoy used such a silicone (or whatever it is). In my unit all of connectors are ruined by oxidation. I decided to replace connectors and cables, all together with small caps. Big ones seems to be OK BTW, I found one critical cap on both PCB's . C17 (4,7u). They were leaky on both boards and caused no sound because of mute circuit low voltage on transistor base. Anyways, It works now… Also, how u guys remove the heatsink???? The screws are under the transformer and tx's screws are under the board covered with heatsink I used brute force and replaced the screws at the end….Shame on you Tannoy!!!!

[midibob]

Re: Tannoy Reveal 6D

Yep, those screws can be tricky and the transformer has to be removed too. A good fitting screwdriver bit is essential and I suspect an impact driver may have been useful too although I don't posses one.

[waveform]

Re: Tannoy Reveal 6D

Thanks a lot for this thread Midibob!
I'm also embarking on my adventure to repair my Reveal 6D.
It was making crackling sounds every so often until one day it got worse and the power LED went off.

I'm wondering if you had to desolder any components to clean the brown glue underneath them i.e. Between the component and PCB?

If anyone has suggestions on how to tackle my board from the pics, i'd really appreciate it, especially on how to clean caps with brown glue on top, or if i should replace them.

[waveform]

Re: Tannoy Reveal 6D

Trying to upload multiple images from an ipad is never a good idea! Here they are:

[waveform]

Re: Tannoy Reveal 6D

Too small, 3rd time's the charm!