Okay, so, as mentioned here I have a Hill Concept 4400.
It looks like this.... http://www.flickr.com/photos/22667645@N07/2180860511/
So, I have looked around for info, and even ended up getting a hold of Malcolm Hill himself, all with the result of absolutely no schematics.
I have been busy and un able to mess with the board but assumed all was more or less okay, but just in the last two days had a chance to check it out.
List of issues grew quick and included 1 dead channel, a few quiet channels, there seems to be some cross talk (when the pre amp on once channel is pushed it shows up on the vu of others, and if it is really pushing, it shows up on most) the talk back button and most of the knobs and faders are scratchy (not so worried but it is there...) At least 4 of the 8 Matrix channels show audio on the vu when there is none and pass some nice hissing, and the big one.
If you are skimming, read this please
The Right channel of the main output, both in the speaker outs, and in the headphone out, is quieter and is missing much of the frequency range. Mostly mid's and some highs are there but no lows...
So, this suddenly looks like a big project for a guy who tinkers a lot but has no training.
The short question is, what do I do to fix this myself.
Here are the anomalies I found so far in the master section (no measurements have yet been taken)
This picture shows a heat spot on a heat sink attached to a TOA2030A in the master section. http://www.flickr.com/photos/22667645@N07/2180865893/
This picture is the op amp itself. http://www.flickr.com/photos/22667645@N07/2181651914/in/photostream/
Seems like a good spot to start, replace these two. I suspect it is a good idea to replace some of the surrounding caps and IC's as well as they could be shot too? Then clean it up and consider a recap of the master sections the sound is still odd... Seem the right step?
I went ahead and started getting an inventory of all caps and op amps in the master section so I can get an idea of what I am in for.
Is it possible I should also rebuild the power supply at the same time, could it have done the damage that I think I see?
It looks like this.... http://www.flickr.com/photos/22667645@N07/2180860511/
So, I have looked around for info, and even ended up getting a hold of Malcolm Hill himself, all with the result of absolutely no schematics.
I have been busy and un able to mess with the board but assumed all was more or less okay, but just in the last two days had a chance to check it out.
List of issues grew quick and included 1 dead channel, a few quiet channels, there seems to be some cross talk (when the pre amp on once channel is pushed it shows up on the vu of others, and if it is really pushing, it shows up on most) the talk back button and most of the knobs and faders are scratchy (not so worried but it is there...) At least 4 of the 8 Matrix channels show audio on the vu when there is none and pass some nice hissing, and the big one.
If you are skimming, read this please
The Right channel of the main output, both in the speaker outs, and in the headphone out, is quieter and is missing much of the frequency range. Mostly mid's and some highs are there but no lows...
So, this suddenly looks like a big project for a guy who tinkers a lot but has no training.
The short question is, what do I do to fix this myself.
Here are the anomalies I found so far in the master section (no measurements have yet been taken)
This picture shows a heat spot on a heat sink attached to a TOA2030A in the master section. http://www.flickr.com/photos/22667645@N07/2180865893/
This picture is the op amp itself. http://www.flickr.com/photos/22667645@N07/2181651914/in/photostream/
Seems like a good spot to start, replace these two. I suspect it is a good idea to replace some of the surrounding caps and IC's as well as they could be shot too? Then clean it up and consider a recap of the master sections the sound is still odd... Seem the right step?
I went ahead and started getting an inventory of all caps and op amps in the master section so I can get an idea of what I am in for.
Is it possible I should also rebuild the power supply at the same time, could it have done the damage that I think I see?
