Genelec 1038A mod

[tgs]

Quick question: has anyone here possibly modded their 1038A's to get rid of the fairly loud pop that comes when you turn the speakers on? Or does anyone know how or if it could be done? I don't think it's harming the speakers or anything, they've survived for 30+ years after all, but it's a bit of a jumpscare.

 

[fazer]

I dont know about 1038’s but My 1031s have a mute transistor that keeps the pop from happening when turning on the speaker. It went bad and started to pop when turned on. I replaced the transistor and it worked correctly again. This might be the problem.

 

[tgs]

I may have assumed that it's not faulty behavior but I've worked in another studio with 1038s and they did exactly the same. Plus on my pair, both speakers are doing the same thing.

 

[pucho812]

I may have assumed that it's not faulty behavior but I've worked in another studio with 1038s and they did exactly the same. Plus on my pair, both speakers are doing the same thing.

It is possible for multiple units to have the same failure

 

[Walrus]

All of the 1032's I've had experience with, from new, all had a turn on click/splat.

 

[nashkato]

you could always , if inside space allows it , put a timedelayed relais before the speakers

 

[tgs]

you could always , if inside space allows it , put a timedelayed relais before the speakers

That's what I had in mind. There's space, I have the amp board removed from the cabinets and mounted in the wall.

 

[Petermaler]

I might be able to help you. It was very unlikely that somebody on the whole internet post something about these speakers just 2 days before I searched deep on the web about some repairs getting done on these amp cards ! I couldn't find many others thread about them... Life is sometimes really surprising.

So, mines are completely defectives (bought them that way), but I own a 1037B pair aswell which they share one of the amp cards with.
The filter and medium/high amp card is nearly the same and so part of the soft start circuit too. This card on the 1038A is basically a 1037A/1037B complete amp which they removed the low amp from. On the 1038 filter and medium/high amp board, the low band signal exit the card (at low level) and goes in a dedicated amp card.

It seems that there's two soft start circuits on those amps, the first one is just on top of 7815 and 7915 regulators on the filter and medium/high amp board, the second one appears to be on the very bottom of the low amp board (it's a capacitor and some diodes and resistors in a small group), the transistor + yellow capacitor just up left to the PSU connectors on that same card appears to be part of the muting circuit.

On the first one you can change the C546 or C556 transistor (don't remember which one is it there but it's written on it) and both small capacitors just next to it (it solved the problem one the 1037B I have that was poping loud at start). About the second, you can change the capacitor (only one on that part of the board) and the transistor.

I'm not at home currently but I can shoot pictures later if needed as my amps are currently removed from the cabinet too.

If needed by somebody else on the internet (it seems to be a reccuring trouble on Genelec amps), if your speaker starts to show a very loud buzz suddenly, on one of my friends 1037B (yes I converted my friends to it) the trouble was solved by replacing the two yellow capacitors just before the 7815 and 7915 regulators, and then the C556/546 (don't remember but written on it) just up to them.

Cheers

P.S. : Sorry for random mistakes, english is my second language.

 

[tgs]

This is absolutely amazing info, thanks Peter! I'll check when I have a moment, and it would be great if you could post some pictures as well as you mentioned.

I'm also in contact with Genelec about this and waiting to hear back from their R&D. I can also relay to them what you said to see if they can verify.

 

[Petermaler]

You're very welcome !

Here are 2 pictures, the first one shows the filter and medium/high amp board with the C556 transistor and capacitors circled in red, second one shows the low band amp with the capacitor and transistor that might be part of the muting circuit.






Yes please ask Genelec, as I mixed my experience (first card) and some observations from another forum where we tried to "reverse engineer" (not sure of the correct meaning) the low band amp board. I think it could help to have a confirmation from Genelec themself...

I'm in contact too with them about another trouble, they can't share schematics (as most of other brands) but they seems to be okay to help us individually.

Long story short, my 1038A are currently amped by Hypex FA503, so I have all the needed time to solve the trouble about my original Genelec amps, and that's my goal to achieve that.


Cheers mate

Peter (Pierre is my actual real name)

 

[thecr4ne]

Hi all, I've got some 1038's I'd like to find more info on re: repair and maintenance. If any of you can point me toward useful sources I'd be most appreciative.
Thanks!

 

[tgs]

Hi all, I've got some 1038's I'd like to find more info on re: repair and maintenance. If any of you can point me toward useful sources I'd be most appreciative.
Thanks!

Check directly with Genelec to begin with, they have been very helpful when I've been in contact with them, even for discontinued items.

 

[tgs]

You're very welcome !

Here are 2 pictures, the first one shows the filter and medium/high amp board with the C556 transistor and capacitors circled in red, second one shows the low band amp with the capacitor and transistor that might be part of the muting circuit.

View attachment 121659

View attachment 121660


Yes please ask Genelec, as I mixed my experience (first card) and some observations from another forum where we tried to "reverse engineer" (not sure of the correct meaning) the low band amp board. I think it could help to have a confirmation from Genelec themself...

I'm in contact too with them about another trouble, they can't share schematics (as most of other brands) but they seems to be okay to help us individually.

Long story short, my 1038A are currently amped by Hypex FA503, so I have all the needed time to solve the trouble about my original Genelec amps, and that's my goal to achieve that.


Cheers mate

Peter (Pierre is my actual real name)

Thanks Pierre! I'll try to find some time in the upcoming week to have a look at this. Might have to order caps, not that much in stock.