kml23956
Well-known member
Put me down for a pair. Which option will depend on the cost.
500 series Sontec / GML type eq
- Thread starter onlymeeee
- Start date
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jackinthebox
Member
- Joined
- Jul 2, 2011
- Messages
- 24
I would love a pair of these!
Put me down for two please.
Jack
Put me down for two please.
Jack
jensenmann
Well-known member
Wow, great project. Congrats, onlymeeee
Since I´m servicing and keeping a bunch of Sontecs in mastering rooms in my area alive I have an opinion on these. While repairing 250s we did a bit of experimentation with caps an chips. There´s a lot of blahblah about swapping chips which in this case is not recommended. We found that sticking with TL071 and 5534 is the way to go. Having said that I had a 250 on the bench which was stuffed with a few LF356 instead of TL071 and the owner did not notice a difference between channels.
He did complain, though, when I replaced the tantalum caps in the filter section with electrolytics. He said that it sounded cleaner than he wanted it to be. So stick with tants in the original spots if you want it to sound like a Sontec 250.
The original in/out circuit is DC coupled. I´d go for a precision chip in these spots. I found the OPA (2)132 series in my measurements to have at least double the DC precision of the OPA(2)134 series, which means less DC offset, but without any difference in sound. I tried hard to find a sonic difference in many circuits but I did not. Double the price, though. Anyway, just to throw another chip into the game.
Since I´m servicing and keeping a bunch of Sontecs in mastering rooms in my area alive I have an opinion on these. While repairing 250s we did a bit of experimentation with caps an chips. There´s a lot of blahblah about swapping chips which in this case is not recommended. We found that sticking with TL071 and 5534 is the way to go. Having said that I had a 250 on the bench which was stuffed with a few LF356 instead of TL071 and the owner did not notice a difference between channels.
He did complain, though, when I replaced the tantalum caps in the filter section with electrolytics. He said that it sounded cleaner than he wanted it to be. So stick with tants in the original spots if you want it to sound like a Sontec 250.
The original in/out circuit is DC coupled. I´d go for a precision chip in these spots. I found the OPA (2)132 series in my measurements to have at least double the DC precision of the OPA(2)134 series, which means less DC offset, but without any difference in sound. I tried hard to find a sonic difference in many circuits but I did not. Double the price, though. Anyway, just to throw another chip into the game.
JeromeMason
Well-known member
I'll take a pair of PCBs.
nielsk
Well-known member
Interesting about the TL0 chips, that has been my experience in many EQs. Seems in an EQ a nice slow chip sounds so much better than a fast chip.
Of course GML used their own op amp, but I have no idea how fast that is...
Is the schematic for the original that indicates component types posted here somewhere?
Of course GML used their own op amp, but I have no idea how fast that is...
Is the schematic for the original that indicates component types posted here somewhere?
petermontg
Well-known member
Have a search for Igors or fabios old boards should be schematic around somewhere.
zenmastering
Member
- Joined
- Jan 26, 2009
- Messages
- 15
Here's the original schematic, courtesy of Gyraf:
http://gyraf.dk/schematics/Sontec_MEP250a.GIF
http://gyraf.dk/schematics/Sontec_MEP250a.GIF
@jensenmann - Awesome. Thanks for the info. So it seems like your findings echo my own.. which is always good!
Yes, I believe the OPA132 is made identically and labelled either 134 or 132 depending on how they test in regard to DC offset.. Lots of options in regards to great sounding fast FET input opamps these days!
PS. The PCBs arrived! But the most innocuous of parts, the lowly screws, got themselves into trouble at customs having come from US. However I've received a card saying they'll be with me on Tuesday! So everything will be ready on Tuesday finally!
Yes, I believe the OPA132 is made identically and labelled either 134 or 132 depending on how they test in regard to DC offset.. Lots of options in regards to great sounding fast FET input opamps these days!
PS. The PCBs arrived! But the most innocuous of parts, the lowly screws, got themselves into trouble at customs having come from US. However I've received a card saying they'll be with me on Tuesday! So everything will be ready on Tuesday finally!
The screws arrived, so all is here finally!
Yes no worries, now everything's in my hand I can confirm price on everything...
It's £165 for a raw kit with all the hard to get parts...
ie. PCBs, front panel, L-bracket, hardware, centre tap pots, polystyrene caps, knobs & coloured caps..
Then for anyone that wants something else, just PCBs etc, just email.. as it's easier than doing different paypal buttons for each combination of items..
Pricewise for that.. it's :
£30 off for knobs & coloured caps.. so, £139 without knobs.
£60 off for metal.. so £79 without knobs or metal.
£5 off for polystyrene caps
£10 for hardware
£10 for centre tap pots
Full details at: www.thedonclassics.com/250eq_diy.html
Any questions or broken links etc let me know.. you may have to refresh browsers etc to see the new website addition...
Yes no worries, now everything's in my hand I can confirm price on everything...
It's £165 for a raw kit with all the hard to get parts...
ie. PCBs, front panel, L-bracket, hardware, centre tap pots, polystyrene caps, knobs & coloured caps..
Then for anyone that wants something else, just PCBs etc, just email.. as it's easier than doing different paypal buttons for each combination of items..
Pricewise for that.. it's :
£30 off for knobs & coloured caps.. so, £139 without knobs.
£60 off for metal.. so £79 without knobs or metal.
£5 off for polystyrene caps
£10 for hardware
£10 for centre tap pots
Full details at: www.thedonclassics.com/250eq_diy.html
Any questions or broken links etc let me know.. you may have to refresh browsers etc to see the new website addition...
guilds100 said:
I've uploaded the footprint with a 2mm grid... So between rows there's 10mm...
I've told Omeg to expect diyers to order these so they gave me a part number to always quote, so they should know the exact way to make it.. Perhaps the distributor is just being extra thorough
bruno2000
Well-known member
guilds100 said:
Great! Will you let us know the results of your work?
Thanks!
Best,
Bruno2000
JeromeMason
Well-known member
I'm currently working on this as well with the US dist. Simple part # prompted some questions back so they may not be familiar with these. If I find something out before the other fella I will post.
Cheers.
Cheers.
