Bohoho, waa, waa, sob, sob, nobody is in a rush to loan me such expensive stuff. That must be one great cartridge.
Has to go back in about 10 days. I doubt I'll be able to get the £975 cost past my sensible and frugal wife
Here's a linestage preamp that outputs about 33V rms before clipping; test result published by Stereophile magazine.
To understand why they did this, free your mind from the assumption that all power amps have the same 1kHz gain as a Blameless amplifier from Douglas Self's books. Have a glance at the power amplifier designs whose PCBs are offered for sale here on this website, at the diyAudio Store. It's more diverse than you might first suspect.
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To understand why they did this, free your mind from the assumption that all power amps have the same 1kHz gain as a Blameless amplifier from Douglas Self's books. Have a glance at the power amplifier designs whose PCBs are offered for sale here on this website, at the diyAudio Store. It's more diverse than you might first suspect.
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Has to go back in about 10 days. I doubt I'll be able to get the £975 cost past my sensible and frugal wife
Build a famous MC preamplifier and cartridge manufacturers are going to throw expensive cartridges at you. It cost them max 10% the street price to build them, anyway. Look at Gerhard example, last time I've checked he was running a 10k Lyra cartridge.
Bohoho, waa, waa, sob, sob, nobody is in a rush to loan me such expensive stuff
It's an evolution of the Coral from the 70s. and same generator as the sumiko blue point, albeit that was the high ouput version. Excel have been respinning the basic design for around 50 years!
If you want to try something different let me know as I've ended up with more cartridges than I think I can wear out in my life and always happy to send one on a holiday rather than it sit on a shelf all lonely.
Me too!
And there are a least 3 preamp designs posted here that can drive buffer PAs. Whilst this is not for the commerical design types I think that makes a lot of sense for the DIYer who is not bound by ancient and outdated convention.
Which is also why I think 20dB of gain in the turntable as a vinyLNA is also worthy of serious consideration.
For my current arm SME Series III (my all time favorite in the price range I can afford) I am currently constrained to a Benz Micro Gold (I have a few other BM, more expensive, but rather low compliance), since it is the only relatively affordable cartridge I could find, in the high-ish compliance range, and I don't want to fill the trough (silicone oil is a mess, don't ask how I found out).
If you have a better high compliance cartridge, I would be interested, let me know.
P.S. For some time I'm contemplating a Clearaudio Concept MC (high compliance, boron cantilever) but I'm still on the fence; before pulling my wallet, I would need to listen to it first, no distributor or reseller seem to have these in stock and installed on a decent TT here in Canada.
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I'm noodling with a high output preamp design myself. Plus and minus 55V supply rails, about 33V rms output, single ended. Double that if balanced. Curiously the first stumbling block to appear has been the power transformer. It isn't easy to find 25VA or 50VA transformers with 2 x 40VAC secondaries, not easy for me anyway.
Ah, fine choice, I have one of those too*. Not currently fitted but need to get around to that. I haven't yet found the ideal mate for it, but have a couple of options. The cartridge I long for (and missed out on on ebay due to being greedy after a couple of relistings) is the signet MK111E which is light and high compliance. I'm also on the hunt for one of the sony XL-MC series and an ortofon MC200. But I believe an audio technica AT33 or AT0C9 should work well and I do have those. Let me get some real world compliance estimates for them and I'll PM you.
* I also have the bonkers ortofon 30H MM wand for it. I have banned myself from ebay until all soldering projects are caught up with!
* I also have the bonkers ortofon 30H MM wand for it
. I have banned myself from ebay until all soldering projects are caught up with!
Great thread, thanks for starting it Bonsai!
I'm not knowledgeable in these matters, and would normally just lurk & learn, but the discussion has included 2 of my favorite topics: Marshall Leach & Tom Holman. So I'm posting in hope that some will be willing to opine/advise on a specific implementation I have in mind.
I have Apt Holman preamp, w/internal expansion plug for an MC pre, and am planning to build an MC card to fit (presently for an Ortofon MC20).
Years ago I built a Leach common-base head amp, and used it successfully (tho sparingly) for a while (until CDs came out shortly thereafter, when my vinyl took back burner for a long while). It worked good, but was shy on gain.
Recently built another Leach, using the current-mirror topology, and am quite happy with the results. Adjustable gain & load.
But I can't stand seeing that Apt MC expansion header go unused, so have a preliminary design to fit. Since I'm not an EE, designing from scratch with BJT/FET isn't in my wheelhouse, so I've used a fairly well documented use case: the AD797 opamp.
It should work well, but it needs dual-rail power, while the Apt expansion header only provides positive voltage. It's simple enough to separately pull negative voltage from the main board, but requires running an extra jumper wire, which would be nice to avoid.
I'm hoping for:
1) single supply voltage
2) gain & load relatively easy to adjust by component selection
3) fairly small real estate (AD797 fits 60 x 50mm PCB)
4) no overly large components (pursuant to small PCB & interference limits)
5) preferably, no huge electrolytic AC coupling caps
So I'm open to suggestions/advise! For starters, are any of the example circuits good candidates for this application? As good as/better than AD797? That could be built small enough to fit?
I'm not knowledgeable in these matters, and would normally just lurk & learn, but the discussion has included 2 of my favorite topics: Marshall Leach & Tom Holman. So I'm posting in hope that some will be willing to opine/advise on a specific implementation I have in mind.
I have Apt Holman preamp, w/internal expansion plug for an MC pre, and am planning to build an MC card to fit (presently for an Ortofon MC20).
Years ago I built a Leach common-base head amp, and used it successfully (tho sparingly) for a while (until CDs came out shortly thereafter, when my vinyl took back burner for a long while). It worked good, but was shy on gain.
Recently built another Leach, using the current-mirror topology, and am quite happy with the results. Adjustable gain & load.
But I can't stand seeing that Apt MC expansion header go unused, so have a preliminary design to fit. Since I'm not an EE, designing from scratch with BJT/FET isn't in my wheelhouse, so I've used a fairly well documented use case: the AD797 opamp.
It should work well, but it needs dual-rail power, while the Apt expansion header only provides positive voltage. It's simple enough to separately pull negative voltage from the main board, but requires running an extra jumper wire, which would be nice to avoid.
I'm hoping for:
1) single supply voltage
2) gain & load relatively easy to adjust by component selection
3) fairly small real estate (AD797 fits 60 x 50mm PCB)
4) no overly large components (pursuant to small PCB & interference limits)
5) preferably, no huge electrolytic AC coupling caps
So I'm open to suggestions/advise! For starters, are any of the example circuits good candidates for this application? As good as/better than AD797? That could be built small enough to fit?
An AD797 is a superb opamp and I use it in my line stages. It’s very low noise for source resistances of < 1k. I’ve seen it used for MC duty where it fares reasonably well from the noise perspective and is on a par with, or a bit better (ie perhaps 3 dB) than a simple discrete BF862 based design. The distortion on the AD797 cannot be best, but it’s a moot point on vinyl where anything < 0.01% means you are well ahead of the cartridge + vinyl capability.
For my money, I’d go with Richard Lee’s MC phono amp, and if you are feeling adventurous, one of the BF862 designs in the compendium. One of them has been built and works well, but it won’t compete with his design on noise - it’s at least 10 dB better.
For my money, I’d go with Richard Lee’s MC phono amp, and if you are feeling adventurous, one of the BF862 designs in the compendium. One of them has been built and works well, but it won’t compete with his design on noise - it’s at least 10 dB better.
Thanks Bonsai!
The AD797 is already in the works, and will be built, just thinking of other alternatives to possibly try.
I'm sure Richard Lees common-base variants are good, but the floating battery versions are a non-starter. Can't be changing batteries in a closed preamp chassis!
His powered version still needs dual-rail supplies, which is the main thing I'd like to avoid, so in that regard alone, no different than the AD797.
I'll look closer at the FET designs you mention, to see if they would fit a small board. Parts count is quite a bit more than the AD797, but if I can squeeze them all in, I may try one of them!
Appreciate the opinion!
The AD797 is already in the works, and will be built, just thinking of other alternatives to possibly try.
I'm sure Richard Lees common-base variants are good, but the floating battery versions are a non-starter. Can't be changing batteries in a closed preamp chassis!
His powered version still needs dual-rail supplies, which is the main thing I'd like to avoid, so in that regard alone, no different than the AD797.
I'll look closer at the FET designs you mention, to see if they would fit a small board. Parts count is quite a bit more than the AD797, but if I can squeeze them all in, I may try one of them!
Appreciate the opinion!
For single supply, you can look at:-
The one on slide 19 (has been built) which is JFET input. But note the BB862 is no longer available
The JLH on slide 5 uses available components and will be quieter than the one above.
If you want lash something up and can tolerate higher distortion, the one on slide 11 is the simplest and is quiet.
The one on slide 19 (has been built) which is JFET input. But note the BB862 is no longer available
The JLH on slide 5 uses available components and will be quieter than the one above.
If you want lash something up and can tolerate higher distortion, the one on slide 11 is the simplest and is quiet.
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