RE: Reichert 300b Flesh and Blood

Posted by drlowmu (M) on March 14, 2012 at 09:39:07

In Reply to: Reichert 300b Flesh and Blood posted by hollywoodpoker@yahoo.com on March 13, 2012 at 22:23:07:

Hi !!

HEY !! The use of two 27K resistors in the driver stage MAY have been intentional, and if not, it should have been.

Two Rs, when EXACTLY matched, will outperform a single R in the same location. You have two wire paths for superior transfer efficiency, two electron flow paths, and two will dynamically outperform a single 13.5K R, as long as their Ohmic values are PRECISELY the same, so that one R does not smear the other.

You can advantageously parallel (exactly-matched) Rs (and even go from one to two TCSS wires), because these so-called "passive" (they aren't, they are active!!) devices can be electrically the same, (but this is seldom the case with paralleling active tube sections.)

Just listen to closely-matched paralleled Rks, versus one Rk, and you will "get it" right away for yourself.

--------------------------------------

As I recall, there is a design flaw in the Flesh and Blood design, as the driver stage and the output stage run off the same B+ supply, and there is NO decoupling of the driver stage from the output stage.

Ripple, PSUD simulated, was about 133 mVAC, which is no problem at all for the low mu finals, but "I" believe 133 mVAC is too much ripple for the driver stage, as it amplifies this ripple as AUDIO signal, to the grid of the 300B. I'd like to see about 2 mVAC or so on the driver stage's B+, so that the ripple is a non-factor when listening.

The 3 HY choke Herbie used BTW was a ESPEY, from Fair Radio, ....3 HY at 24 Ohms DCR. I personally baptized Herbie, (and his buddy JC), into low DCR way back then, and turned Herbie on to my favorite sounding choke. I have just two of those ESPEY babies left if anyone is interested.

Also, by today's standards, the 5R4 rectifier tube choice is whimpy / high Z, but, at least, its a directly heated vacuum rectifier. I'd use a 5U4 or a 5V3 instead today.

Three stage amps to power a 300B are destined to only be "average" in performance.

They should be just two stages, and I prefer DC amps, not amps with series-cap-couples. Ugh, there are TWO 0.1 uF cap-couples in the case of the F and B, and a direct couple will "creme" that topology.

A two stage will always be more transparent sounding than a three stage amp. A two stage amp is "the best configuration" IMHO for highest possible audio performance in the SE world. The extra stage is not really needed, you "pay a price" for the added third stage complexity, anti-transparency and a cap couple or even a unnecessary transformer couple.

So, maybe that is why we don't see a lot of Flesh and Bloods these days. You asked, I answered. Just my humble opinion. Cheers.

Jeff Medwin

This post is made possible by the generous support of people like you and our sponsors:

Follow Ups Full Thread

Topic - Reichert 300b Flesh and Blood - hollywoodpoker@yahoo.com 22:23:07 03/13/12 (20)

RE: Reichert 300b Flesh and Blood - Mike C 13:17:28 03/14/12 (1)

RE: Reichert 300b Flesh and Blood - hollywoodpoker@yahoo.com 15:39:21 03/14/12 (0)

RE: Reichert 300b Flesh and Blood - drlowmu 09:39:07 03/14/12 (4)

RE: Reichert 300b Flesh and Blood - kyle 10:47:58 03/14/12 (3)

RE: Reichert 300b Flesh and Blood - SteveBrown 12:11:11 03/14/12 (2)

RE: Reichert 300b Flesh and Blood - kyle 08:14:48 03/15/12 (1)

RE: Reichert 300b Flesh and Blood - Wojciech 23:32:44 03/17/12 (0)

RE: Reichert 300b Flesh and Blood - SteveBrown 08:56:03 03/14/12 (0)

RE: Reichert 300b Flesh and Blood - danlaudionut 04:08:17 03/14/12 (2)

Hi Dan..except Herb used 2 * 27 k resistors on purpose - Bas Horneman 07:27:05 03/14/12 (0)

RE: Reichert 300b Flesh and Blood - hollywoodpoker@yahoo.com 06:08:22 03/14/12 (0)

RE: Reichert 300b Flesh and Blood - Bas Horneman 02:15:59 03/14/12 (0)

RE: Reichert 300b Flesh and Blood - Frihed89 00:01:40 03/14/12 (7)

RE: Reichert 300b Flesh and Blood - hollywoodpoker@yahoo.com 00:21:39 03/14/12 (6)

OK - Frihed89 11:00:43 03/14/12 (1)

nice - richardl 15:18:43 03/21/12 (0)

Would you like someone else to do it for you? - Bas Horneman 02:01:26 03/14/12 (3)

RE: Would you like someone else to do it for you? - xaudiomanx 05:53:27 03/14/12 (2)

RE: Would you like someone else to do it for you? - Frihed89 08:09:09 03/15/12 (0)

If he was a teenager I might be persuaded to - Bas Horneman 07:38:22 03/14/12 (0)

Follow Ups

RE: Reichert 300b Flesh and Blood - drlowmu 09:39:07 03/14/12 (4)

RE: Reichert 300b Flesh and Blood - kyle 10:47:58 03/14/12 (3)

RE: Reichert 300b Flesh and Blood - SteveBrown 12:11:11 03/14/12 (2)

RE: Reichert 300b Flesh and Blood - kyle 08:14:48 03/15/12 (1)

RE: Reichert 300b Flesh and Blood - Wojciech 23:32:44 03/17/12 (0)

RE: Reichert 300b Flesh and Blood

Post a Message!