Search found 700 matches

by Gold
Wed Aug 26, 2015 10:25 am
Forum: Pro Audio Design
Topic: Flat Phono Preamp Based on John's P10 and 2SK389
Replies: 248
Views: 455110

Re: Flat Phono Preamp Based on John's P10 and 2SK389

I'm very close to hitting the "submit" button for a small ProtoPro order on the EQ/Monitor switcher. While setting levels using test tones from the CBS STR-100 disc I noticed something very curious: MM cartridge crosstalk (1kHz AT AT-96) is out of polarity . Left-only modulation is produc...
by Gold
Sun Aug 16, 2015 8:31 pm
Forum: Pro Audio Design
Topic: A Flat Moving Coil Preamp Using Paralleled Amplifiers
Replies: 42
Views: 103623

Re: A Flat Moving Coil Preamp Using Paralleled Amplifiers

Paul, which SPU is yours? From the Ortofon website, I have the Meister at 1R5 to the Royal at 6R. I'd like to dream up a version for Wayne to set a Noise Benchmark at least. It's the SPU Classic N. It is the most vintage like one they make but without the head shell. I've been told that the head sh...
by Gold
Sat Aug 15, 2015 11:45 am
Forum: Pro Audio Design
Topic: A Flat Moving Coil Preamp Using Paralleled Amplifiers
Replies: 42
Views: 103623

Re: A Flat Moving Coil Preamp Using Paralleled Amplifiers

I don't think you need to worry about DL103 tracking at 2gm with its 0.5mil conical stylus. Though the indentation eqn isn't exactly proportional to pressure this is 'equivalent' to (0.2/0.5)^2 x 2gm = 0.32gm with a 0.7x0.2 elliptical Besides there have been several studies which show its tip mass ...
by Gold
Wed Aug 12, 2015 10:07 pm
Forum: Pro Audio Design
Topic: A Flat Moving Coil Preamp Using Paralleled Amplifiers
Replies: 42
Views: 103623

Re: A Flat Moving Coil Preamp Using Paralleled Amplifiers

I have an Shure SE20 and SE22. The SE20 is discrete and the SE22 uses an IC opamp. I think the SE20 was the same as a UREI 1122. I'll look at the boards in the SE22 and see if they say UREI on them. The SE20 boards say UREI on them.
by Gold
Tue Aug 11, 2015 5:37 pm
Forum: Pro Audio Design
Topic: A Flat Moving Coil Preamp Using Paralleled Amplifiers
Replies: 42
Views: 103623

Re: A Flat Moving Coil Preamp Using Paralleled Amplifiers

mediatechnology wrote: Have you had any luck getting those re-cantilevered?
I haven't tried. It looked like it was almost as expensive as getting a new one. When mine broke I needed an immediate replacement. I know Soundsmith hot rods them.

I'll look for the broken one but I probably tossed it.
by Gold
Tue Aug 11, 2015 2:40 pm
Forum: Pro Audio Design
Topic: A Flat Moving Coil Preamp Using Paralleled Amplifiers
Replies: 42
Views: 103623

Re: A Flat Moving Coil Preamp Using Paralleled Amplifiers

I only have one DL103 which I'm using. I could send you the SPU I have with or without the transformer. It's pricey so you'd have to be careful but I'm happy to do it. It would be a good test since the output is so low. I destroyed the stylus on a DL103 a while ago. I can see if I still have it.I co...
by Gold
Tue Aug 11, 2015 1:24 pm
Forum: Pro Audio Design
Topic: A Flat Moving Coil Preamp Using Paralleled Amplifiers
Replies: 42
Views: 103623

Re: A Flat Moving Coil Preamp Using Paralleled Amplifiers

I'm using the Lundahl 1678. 1:16 for the Denon 103. I have a 3k83Ω termination resistor in parallel with the Shure SE22 47kΩ input termination resistor. The SE22 data sheet says there is 54dB of gain. I'm using at least 50dB gain in this setup to get 7cm/sec lateral to +4dBu. I have an extra set of ...
by Gold
Tue Aug 11, 2015 11:59 am
Forum: Pro Audio Design
Topic: A Flat Moving Coil Preamp Using Paralleled Amplifiers
Replies: 42
Views: 103623

Re: A Flat Moving Coil Preamp Using Paralleled Amplifiers

I am generally not a fan of audio transformers, and even made a solid state MC version of one of my preamp kits back in the day. That said an audio step up transformer could really help dealing with such low Z transducers. Since we are dealing with such low power levels the transformer doesn't need...
by Gold
Sun Aug 09, 2015 6:30 pm
Forum: Pro Audio Design
Topic: A Flat Moving Coil Preamp Using Paralleled Amplifiers
Replies: 42
Views: 103623

Re: A Flat Moving Coil Preamp Using Paralleled Amplifiers

Any idea of the Rs of these 3 groups of MC cartridges? Off the top of my head I'd say that an Ortofon SPU would be in the low output category with a very low source impedance. A Denon 103 would be in the medium category and the DL-110 that Wayne mentioned would be in the high category. The SPU is m...
by Gold
Thu Jul 09, 2015 12:57 pm
Forum: The Peabody Lounge
Topic: An Honest Telemarketer?
Replies: 6
Views: 8928

Re: An Honest Telemarketer?

The best phone conversation I've heard lately was when i was visiting Richard at Leeds Radio. He suffers no fools. He got a call from someone on the sub continent calling themselves Steve. Before the guy could get a word in Richard asked him for a good biriyani recipe. He wouldn't quit. Finally the ...