Revisiting another old friend. (long)

70.230.182.243

Posted on October 23, 2009 at 18:21:05

drummerwill
Audiophile

Posts: 292
Location: St Louis Mo.
Joined: January 7, 2003

Been playing around with preamps, DIY stuff. I like the drive of an active preamp and go nuts over the clarity of a passive.

Recently was using a Preassembled Marantz 7 copy board with my DIY power supply. With decent caps it sounds pretty good.

I've had a DIY type 26 Choke loaded with Output trannies for about 5 years now. I've been tweaking this thing forever, but even with Ronan CCS regulators on the filaments it always hummed enough to be distracting.

So Duh ! I never thought about increasing the capacitance in the regulators until 5 days ago. Sure enough after the 10000uf input cap it had 330uf caps in the frist stage and 150 uf in tht final. I increased the first to 4700uf and the final to 1200uf. This seemed to do the trick.

26 DHT preamp trumps both the Marantz 7 copy and the passive.
DHT magic is something else!

Have fun!
Willie

RE: Revisiting another old friend. (long)

drlowmu

19:07:21 10/23/09

RE: Revisiting another old friend. (long)

drummerwill

11:33:18 10/24/09

RE: Revisiting another old friend. (long), posted on October 23, 2009 at 19:07:21

drlowmu
Manufacturer

Posts: 4649
Location: East of Kansas City
Joined: January 10, 2005

Hey Willie,

Cool post. It was SO wonderful to meet you at RMAF, and Saturday night with you and Mark Gall in the Serious Stereo suite was fun. I was delighted you two dudes could listen some !!

I found the Ronan regulator circuit did not drop enough voltage, across each active device, I would say this is a design suboptimization.

The devices (may) sound better, and CERTAINLY measured far better, mVAC ripple wise, when the voltage across each regulator is increased. How much? Golly, this was twelve years ago. But if it is dropping 3/4 of a volt, double it, add heatsink capability and listen, measure that. Let me know how it goes and what it sounds like, PLEASE !!

Keep slinging solder man, and drumming too !!

Jeff

RE: Revisiting another old friend. (long), posted on October 24, 2009 at 11:33:18
drummerwill Audiophile Posts: 292 Location: St Louis Mo. Joined: January 7, 2003	Thanks Jeff I really enjoyed my first RMAF and looking forward to next year. The saturday night in the Serious Room was certainly "Serious" stuff! And talking with Dennis was hoot, he really knows good guitar picker when he hears one. It's great finally meet face to face some of the people that make "Our" Audio community a great place to be! Have fun! Willie

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Revisiting another old friend. (long)

70.230.182.243