MacCormack Upgrades from SMc Audio?


Hi all, My Phono Pre-Amp is a MacCormack Micro Phono Drive bought back around '96.

Just doing some surfing today, I stumbled upon Steve MacCormack's site, and see that he lists two upgrade revisions for the Micro Phono Drive, and also produces a better outboard Power Supply versus the original Wall Wart that came with the unit.

From the sound of his description, his better revision B upgrade essentially replaces just about every component in the unit, going to better Burr-Brown Op Amps, trimmed RIAA Stage, Vishay components, etc, etc. The cost of this upgrade is said to be $500, and this was actually what I paid for this unit new when I bought it.

Also, the Outboard power Supply costs $275, WBT RCA's another $60 Whattya think?
markd51
Mark,

You might want to call him... I think he probably answers his phone more regularly than answering his email.
Hi Mark -

Thanks for your interest in my work. One correction: the $500 upgrade you describe is the Revision A - not the "B." You are absolutely correct that the Rev A is a complete rebuild, including circuit topology improvements as well as a full set of the best resistors, capacitors, wire, and jacks. The result is a very serious phono stage, and the people that have had this work done have expressed a lot of enthusiasm about the finished product. It's an across-the-board improvement.

The new power supply (the Micro Power Station) is optional, but recommended. In truth it is a relatively small upgrade over the original wall-wart, but it *is* an improvement and it does allow you to use a good after-market AC cord.

Regarding your e-mail question about the gain, I am a little surprised that you aren't hearing any clipping when running your high-output Glider with the High gain setting. There is no danger of hurting anything so it's no big deal, but watch out for phono stage clipping on highly modulated records.

That's all I have for the moment... I am currently out of town but will be back in my office on Monday the 27th if you wish to call.

All my best to you and other 'Goners,

Steve McCormack
www.SMcAudio.com
Thank you Steve for you kind, and helpful reply, and responding while you're away.

I'll get back with you by phone about my interests with the upgrade soon.

I'm going to take your advice, and try the Micro Phono Drive at the Lower Gain Setting for now, and see how I like it. Thank you again Steve! Mark
Hello again Steve/All,

After changing the gain settings again (to low gain on the Pre-Amp), I find that I really have to push my Mac Amps quite high to get volume in what I feel is an acceptable level.

I can recall this issue some years ago, when I first got the unit and did the set up, and stayed with the high gain setting ever since.

I have never noted any clipping on any LPs of mine, but I will admit, the high gain is a little bit on the "hot side", and that a gain level that would be in between the two factory settings would've been perhaps ideal-better.

My Benz Glider which was the very first version when it first came out years ago, is claimed on the spec sheet to have a 1.9Mv Output at 3.54 cm/s, but on the actual Lab test graph-sheet my personal Glider is tested at 1.8Mv.

I've read that the newer Glider H2 is spec'd at 2.5Mv.

Back when I bought mine ('96), there was no such thing as the Medium Output Glider, but there was the standard low output Glider if I recall. Mark

Hi again, Mark -

No problem with using the High-gain setting if you are not running into overload problems - go ahead and use the setting you like best. One thing you might try is loading your Glider with something below the standard 47KOhm input load. You could try loading resistors in the 10K / 5K / 1K range, for instance. It is possible that you might find an input load that will reduce the drive level slightly and improve the sound quality. See what you think.

Best regards,

Steve McCormack
www.SMcAudio.com