GB for DC coupled B1 buffer with shunt PSUs

[nycavsr2000]

Originally Posted by regiregi22

Can we have a picture of your collection of jewels?

Sorry bud, they haven't arrived yet. Not until September.

Anand.

[Atilla]

Can I substitute the bipolar transistors with different models?

For example the BC550/560 ones with 2n3906/2n3904? Maybe something for the BC-517 as well? Not that they're hard to find or anything, but I've a huge box of transistor soup here - 2n3XX, 2n5XX, A, S, C - all kinds of prefixes basically and if I can use them already, I don't see why not.

I guess finding replacements for the relay drivers isn't a problem, but what about the ones in the regulator itself?

[AndrewT]

the FET driver needs medium speed (fT~200MHz) and highish gain (hFE>300).

The relay driver needs medium Ic (>100mA) and good gain at high current (>200 @ 5mA)
hFE>150 @10mA and 20mA saturated @ Ic/Ib>10 for 0.1Vce.

If using a 5V relay, then maybe Ic>150mA, 40mA sat @ Ic/Ib>10 for 0.1Vce.

But, watch all the different pin outs.

[Tea-Bag]

Salas and I are going to attempt to re-issue some Mesmerizes. We looking for at least 50 units to sell.
Figured that this won't directly interfere with Blue Edition demand, so it's a good time to offer it.
Some people really liked this gadget because of it's relay switched inputs.
We are going to open a potential group buy sheet for a couple of weeks to see if there is real interest. The price would be 14.00 dollars, a single sided board, and would use 2 oz copper instead of 1.

Here is a blurry pic of my original DCB1 Mesmerize.

Here is the sign up sheet.
https://spreadsheets.google.com/ccc?...DeHBDamc&hl=en

[Atilla]

Originally Posted by AndrewT

the FET driver needs medium speed (fT~200MHz) and highish gain (hFE>300).

Right, that would eliminate the 2n39XXs in that case, as they're below those specs. I'll see what else I've got in stock.

Originally Posted by AndrewT

The relay driver needs medium Ic (>100mA) and good gain at high current (>200 @ 5mA)
hFE>150 @10mA and 20mA saturated @ Ic/Ib>10 for 0.1Vce.

If using a 5V relay, then maybe Ic>150mA, 40mA sat @ Ic/Ib>10 for 0.1Vce.

Those I'm sure I can find in the "generic transistor" bag.

Originally Posted by AndrewT

But, watch all the different pin outs.

This is actually worrying me more than going trough the datasheets for electrical characteristics. I'll end up getting 1 transistor the wrong way, because I forgot it's using a different pinout, sooner or later

Thanks AndrewT, that's a lot of help, as usual.

[Eric]

As usual... I'm late to the party! I've spent the past 8 months building my long-awaited Aleph-X amps and open baffle speakers, and I miss all of the action for a nice preamp. Anything left for me to buy to get in on the action?

Eric

[Marra]

Will the new Mezmerize board have the beefed up power supply of the Blue Hypno?

[AndrewT]

will it incorporate the remote sense as adopted for all the later versions?
will it include a better relay delay/driver?
will it wire in the delay relay properly?

[Salas]

Originally Posted by Marra

Will the new Mezmerize board have the beefed up power supply of the Blue Hypno?

No, its not a redesign, just a better quality pcb reissue. There were some voices about missing the Mez full pre, so we thought we can try out and see if there will be some minimum interest in signing up for it. It was something we promised earlier in this thread. That one is not normally being gauged for a reg only heavier use, so its psu is adequate for uF.

[Salas]

Originally Posted by AndrewT

will it incorporate the remote sense as adopted for all the later versions?
will it include a better relay delay/driver?
will it wire in the delay relay properly?

There is no remote sense in such boards. Maybe you mean several later reg designs of mine, but not pcbs.
Crt is not around to make any tweaks, its the old Mez.