Tapco C12 project finished! Thanks all for the advice!

[ebartlet]

I have finished re-chiping and re-capping my tapco C12. I am very, very pleased with the sound. Compared to an unmodded channel and a Mackie 1604VLZpro, It was like a veil was lifted. There is detail without harshness. Very smooth. The EQ is smooth as well, not brittle sounding on the high end. I am not afraid to boost EQ anymore!

Here is what I did based on everyones advice and doing searches on this board:

Replaced all 4558's with 5532's. I kept the LM301's in the output section.

All coupling caps were replaced with Vishay BC series axials.

I went with Orange drops (polyprop) in he EQ.

Kemet tantalums on the line in cap and to and from the EQ.

Replaced all ceramic bypass caps with polyester caps.

Everyone said to rebuild the power supply. I respect everyones advice here, especially because most of you have more experience than I do. But after sizing up the PS components (believe it or not, this is one of those situations where the PS TX is bigger than it needed to be, off the shelf high volume discount part maybe?), and looking at an empty wallet, I opted to try to make the stock PS work. I did upgrade the filter caps and changed the current sense resistors to a value that would allow more current without limiting. Stock current draw was 329mA, after re-chiping 563mA. After being on all day, the TX and the heatsink with the pass transistors are only warm to the touch.

According to other posts, benefits to building a new PS with a toroidal tranny would include better noise performance, which isn't a big deal as the noise floor is low enough for the type of music I typically record. Besides, I need to do some more recording gigs before I can afford anymore DIY.

Thanks everyone for your insightful posts. This board sounds so much better than the mackie I was using that I almost feel ashamed to have let some of my past recording jobs out the door. :grin: :grin: :grin:

A round for everyone... :sam: :sam: :sam: :sam: :sam: :sam: :sam: :sam: :sam:

Related threads:


http://www.groupdiy.com/index.php?topic=3317

http://www.groupdiy.com/index.php?topic=3404

 

[MikoKensington]

That thing looks really cool. I'd love to know what it sounds like.

 

[radiance]

Very nice! Did you also give it a new paint job?

 

[ebartlet]

[quote author="radiance"]Very nice! Did you also give it a new paint job?[/quote]

Yes, I figured since it was no longer stock, it shouldn't look stock either. Its easier to impress clients with something "custom" than it is with the word "tapco"...

There is a certain red helios I dream about...

 

[Consul]

That looks great! I wish I had the money to keep all of my DIY going. I'm barely clearing my bills as it is.

Modding an old mixer to clean it up sounds like a good path to take, rather than building a whole new one.

 

[NewYorkDave]

Wow... I guess sometimes you can make a silk purse from a sow's ear. If it sounds as good as it looks, then that's one nice little mixer you have there. Good job.

Have you taken before and after measurements, or are you just gauging the improvement on listening tests?

 

[ebartlet]

[quote author="NewYorkDave"]Wow... I guess sometimes you can make a silk purse from a sow's ear. If it sounds as good as it looks, then that's one nice little mixer you have there. Good job.[/quote]

Thanks

[quote author="NewYorkDave"]
Have you taken before and after measurements, or are you just gauging the improvement on listening tests? [/quote]

I haven't done any offical tests yet, although I have some sound files which I ran through it and re-recorded before modifying. I intend to play the same files through and compare. I understand the whole placebo thing, but the improvement is so apparent (I didn't have to listen for it), there is no doubt it is way better. I ran some tracks through that I had recently mixed and released. Put up a rough mix. There is more space and depth around each element of the mix. All I could say was wow for a few hours... I am very geeked about this thing!

 

[NewYorkDave]

Everyone keeps looking for a "better" chip, but it's hard to beat the good old 5532, isn't it? :wink:

Enjoy your stylin' new mixer!

 

[Mbira]

That looks sweet! Very, very nice.

Joel