MiamiBoy
Well-known member
moamps said:
Great, so I already have the mod ;D
Thanks.
Any Av@l0n 737 compressor mods exist?
- Thread starter juniorhifikit
- Start date
Help Support GroupDIY Audio Forum:
Great, so I already have the mod ;D
Thanks.
pucho812
Well-known member
For starters... the card in question should be card 5600-7374 iirc
It’s a square card that mounts to the mother board and is directly behind the bulbs for the VU meters sandwiched between the psu chassis and bulbs.
There are 2 electrolytics on the card which you need to concern with.
The first is part number c5, originally was 10uf and dropped to 1uF for babyface mod. C5 Control’s the attack time constant while the pot allows you to be variable in the range. 10 uf was the original value unless modified and gives a varimu vibe, slower attack then other comps. fwiw at fastest attack time, it takes it from 200ms to 100ms. If you really want to get funky can try lower then 1uF but I don’t know how low you can go before it’s unusable, I never tried and 1uF works very well. On mine I added a switch which switches caps in there so I can get 1uf(modern) or 10uf(vintage).
New units from the factory made pre 2012 had the mod as an option. For 50 bucks they would do it or would send you parts to do it. Units made from 2012 up to currently and beyond already have the 1uF cap in there. This was due to customer demands.
The second cap, of which I forget the part number controls the release time constant. Originally it was 10uf as well and I don’t believe Avalon made any changes to that over time.
Again you can drop that 1uF and experiment beyond that but I don’t know how useable it would be. Again I added a vintage modern switch to mine.
It’s a square card that mounts to the mother board and is directly behind the bulbs for the VU meters sandwiched between the psu chassis and bulbs.
There are 2 electrolytics on the card which you need to concern with.
The first is part number c5, originally was 10uf and dropped to 1uF for babyface mod. C5 Control’s the attack time constant while the pot allows you to be variable in the range. 10 uf was the original value unless modified and gives a varimu vibe, slower attack then other comps. fwiw at fastest attack time, it takes it from 200ms to 100ms. If you really want to get funky can try lower then 1uF but I don’t know how low you can go before it’s unusable, I never tried and 1uF works very well. On mine I added a switch which switches caps in there so I can get 1uf(modern) or 10uf(vintage).
New units from the factory made pre 2012 had the mod as an option. For 50 bucks they would do it or would send you parts to do it. Units made from 2012 up to currently and beyond already have the 1uF cap in there. This was due to customer demands.
The second cap, of which I forget the part number controls the release time constant. Originally it was 10uf as well and I don’t believe Avalon made any changes to that over time.
Again you can drop that 1uF and experiment beyond that but I don’t know how useable it would be. Again I added a vintage modern switch to mine.
MiamiBoy
Well-known member
The switch sounds like an awesome mod. Do you have pictures to share?
I believe the pic I’ve attached was C5.
An official Avalon repair shop (Myring Wiring) confirmed that this would be the fastest achievable attack time.
So I don’t know if I should be messing with this and install a smaller cap.
I still think it’s too slow for me, therefor unusable unless I use it as a limiter.
It’s not like I’m trying to expect a 1176 attack time, but 100ms is just too damn slow for me. I record a lot of rap vocals.
The release time is fine.
I believe the pic I’ve attached was C5.
An official Avalon repair shop (Myring Wiring) confirmed that this would be the fastest achievable attack time.
So I don’t know if I should be messing with this and install a smaller cap.
I still think it’s too slow for me, therefor unusable unless I use it as a limiter.
It’s not like I’m trying to expect a 1176 attack time, but 100ms is just too damn slow for me. I record a lot of rap vocals.
The release time is fine.
pucho812
Well-known member
I know the guys at myring wiring. they are correct as that is factory authorized. Anything else is non factory. good thing I spent time as avalon's head service guy so I can tinker a little beyond that as needed. As for the switch, it's a DPDT switch, where the capacitor solders into the PCB, I wired the common terminals. pay attention to polarity. with the switch up, I get common to a set of pins and have one cap wired to them. with the switch in the opposite position, I get common to the other set of pins where I have the other cap value. Because I like things neat, I have a blank panel I put the switches on and I drilled a little hole into the lid. the wires run through there. I have the hole at the edge so I can still pop off the lid for any service needs without having to un-solder anything. I did the same for my 2055 eq, however the switches here change resistor values so I can get full gain or 1/2 gain on the pots making it closer to a 2077 mastering eq.
I never found the compressor to be too slow, guys like dr. dre prefer it over other units. In fact dre's chain is a 1073 preamp and eq into the 737 for the compressor, but like anything else opinions vary.
I never found the compressor to be too slow, guys like dr. dre prefer it over other units. In fact dre's chain is a 1073 preamp and eq into the 737 for the compressor, but like anything else opinions vary.
