Rowe-Ami R87 Sound problem

[CHRIS-F]

Hi Guys,

I have a little problem on my Dad's Rowe-Ami R87, the sound disappears intermittently at random, sometimes it will play fine for weeks then when it feels like the sound goes off, if I turn the volume right up the sound is there but only very low, I don't think it only happens when it's warmed up because it is random at different time sometimes after first switching on.

Where should I start to diagnose the problem, is it likely to be the amp, pre amp, output transformers? is there any tests I can do? is it a common problem to the R87?

Thanks in advance,
Chris.

[ed12]

a=if the amp-pre-amp have never been capped
now is a great time to do it...
your problem is in the >avc< circuit
this if tube is a 12ax7 and or a 12av7 ?
u c the avc is atomatic volume control.,what it dose is mute the box durning stand-by

ed

[ami-man]

Hi Chris,

The amplifier more than likely a Rowe Ami 6-09931-01 130 watt amplifier needs checking for dry joints (cold joints USA) to the connection pins on the driver boards and pre-amplifier.

If you were in Europe I would suggest that you send it to us for testing/repair, if you are in the USA then I would suggest AB Leisure.

Regards
Alan

Alan Hood
ami-man
UK

[CHRIS-F]

Thanks Guys, I haven't had a chance yet to check the model number but doing a search on Google for "6-09931-01 130 watt amplifier" it looks like the same model to me.

First things first it's never been re caped is there a specific type of cap to use for audio applications or would I just use any good quality caps? second point is I have tried a spare amplifier with the same results, it may be possible that they both have dry joints but could something else be causing it? possibly like Ed said a volume control that lowers the sound when the record isn't playing? I have spoke to you before Alan you advised me that the outputs look like they are wired for either extra speakers and a wall box or possibly because one of the channels was not working, but having said that it has been playing fine for years wired that way, I am a bit reluctant to re wire the output transformers "you know how dad's moan when things go wrong" :-) I will re wire them eventually, but I would like to get to the bottom of the fault first and get it working the way it was. I have a few spare parts, is there a way to check the output transformers possibly for resistance???

I would like to try and get it going myself as I am learning about electronics as I go, but if I can't get to the bottom of it how much do you charge Alan to test/repair the amp?

Thanks again guys :-)
Chris.

[ami-man]

Hi Chris,

I guess we must have spoken to each other at some point.

Re the caps I only change this when required in this type of amplifier. The fault will be down to something else it is rarely the caps on this era of amplifier. It does happen but if it does it is usually the two or four smoothing caps on the power rails that tend to be at fault.

I charge £45 for testing & £75 for repairs plus delivery charges and VAT.
Dry joints are covered in the testing fee, the only other item you would have to pay for would be any output transistors if required.

If you send me a picture of the colours of the cables on the output package, I can let you know where they should be, if the violet and pink are both on the left or righthand side then this is usually an indication that one side of the amplifier has failed and to get sound these wires have been put onto one side of the amp.

You usually find this out after you have just bought a jukebox off of Ebay or a similar site.

Regards
Alan

Alan Hood
ami-man

alan-hood@datex.co.uk