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I just put in a pair in my Heath AA-11 preamp and made an already incredible preamp that much better..The backgrounds and the upper crust extension and midrange depth is more pronounced and the noise floor dropped .43db on measurement.That's quite a bit as it was already a quiet preamp after I rebuilt and upgraded it.
I use the insulated ones in the preamp and these are 600v at 4 amps but you can use 2 amp but they aren't much cheaper.These diodes are only a couple bucks each but well worth it. I'm addicted to these things.
"For every complex problem there is an answer that is clear, simple, and wrong" H. L. Mencken
Follow Ups:
Are you using in tube pre and power amps and do you heat sink them?
Do you think they'd benefit a 300watt per channel MOSFET amps?
Thanks,
Scott
Scott,
For 600 PIV use Cree's C3D02060F. For 1200 PIV use Cree's C4D02120A. Both are rated for 2 A., which should be quite sufficient in tubed circuitry.
The fact that Schottkys are switching noise free should help in SS amps too. What sort of PIV and current capability fit your 300 WPC situation? Parts availability and possibly cost may be issues.
Eli D.
Mike, what's the deal with using the Cree ZRec SiC schottkys in series? You need voltage equalizing resistors selected to pass the equivalent reverse leakage current or something like that?Sonically, three different pieces of equipment I have used these in have a black background - very nice. But, wondering if in one case it might possibly add a little edge to the mids, but I am not sure.
I recall reading something at Vacuum Tube Valley a while ago where they seemed to favor schottkys
Edits: 12/28/16 12/28/16
Schottkys have very low, almost non-existent, out of band switching harmonics. So, other than through a higher and very clean HT DC voltage, how can you 'hear' them?
IME the sound quality improvements from soft recovery (SR) quiet SS diodes in valve amps is the far higher energy storage you can achieve:- they don't have severe PIV limits and the HT is also higher.
The energy storage is a f'n of the voltage squared so added to 300V even 10 extra volts has a large effect.
Warmest
Tim Bailey
Skeptical Measurer & Audio Scrounger
current output is a function of capacitance straight up. In this case, I=C*di/dt...more capacitance results in less change in voltage for any given signal.
cheers,
Douglas
Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.
Putting balancing resistors on series connected diodes is nothing new.They did this back in the 60s on the Allen Organ amps but you can use 1/4 watt resistors there.This is stock and needs rebuilding but notice the balancing resistors.
"For every complex problem there is an answer that is clear, simple, and wrong" H. L. Mencken
Without voltage equalizing resistors, there is CONSIDERABLE risk of cascading parts failures.
Eli D.
Mikey,Are you talking about a T0-220 package with isolated tab like the one in the link?
Edits: 12/28/16
I modified a Dynaco PAS years ago (Vorhis Last PAS) and used 1N4007s to replace the selenium rectifier in the filament supply.
After reading so much about Schottky diodes here on the Asylum, and with Eli Duttman calling 1N4007s "bat guano", I decided to try replacing them with two 31DQ10, 3 amp, 100V Schottky diodes.
There was a noticeable improvement in the sound of my preamp, for a total cost of about $1.
Mikey how are you mounting these in your restorations, VS the axial lead type diodes. I just ordered some but not sure how to set them up, can you post some images?
Jeff
When you have the Schotky lettering facing up at you and pins pointing down,the pin to the right would be the same as the banded end.
"For every complex problem there is an answer that is clear, simple, and wrong" H. L. Mencken
Mikey, right I get that on the direction, but what I was wondering is how you are physically mounting the diodes and connecting those leads...in other words the axial type are held suspended by solder joint, and or mounted in a cradle clip like on the citation II. .. But these guys are like chips with the leads facing out like a fork...
Thanks!
J
You can buy 5 A. rated parts and saw the metal tabs off. You definitely don't want the tabs sticking up into the air and acting as an antenna for EMI/RFI. Form the leads with pliers.
Eli D.
Any suggested tips or techniques for removing the tabs from the TO-220 tab?
Eli
I bought some that are insulated that are fantastic.
"For every complex problem there is an answer that is clear, simple, and wrong" H. L. Mencken
Like different rectifier tubes make a sonic difference, I am sure solid-state diodes would also make a difference.
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