John Curl's Blowtorch preamplifier part II

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I was talking about the passive preamp John, not the blowtorch

as with many here, I think despite the accompanying rhetoric and somewhat magical claims, which I dont care for, the CTC BT is an impressive discrete preamp and I have never thought any different.

if you must have empty space, leave it empty, dont fill it with an extra 10x as much air-wired signal path as needed. especially when you actually stock the very parts needed to avoid it, but choose not to use them on a single one of the all passive preamps. it wouldnt sell as much wire though. with the erm... shaft extensions installed, the direct out could have 5cm or less wire and max 10cm (easily less) for the transformer coupled out. there is no good reason for it.
 
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Now, WHY did I put up someone else's passive line preamp for people to view?
IF the critics here could actually see the GOOD in something, rather than the 'need for improvement' in virtually every case, then we might go forward.

I have a nice passive preamp, Roderstein resistors and nice Shalco switches it is as transparent as I can tell. The fact that it cost only $250 might degrade it it the minds of some.
 
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No it would not be practical to use shaft extenders, because IF the customer wanted a balanced input system, then we would run out of room, IF we used shaft extenders.

Why would you be out of room? If you were able to throw all that in with the input selector and volume control at the front of the chassis, why couldn't you put the same stuff in with the input selector and volume control at the back of the chassis and moving the electronics toward the front of the chassis?

Also, we would have to find an alternate way to securely mount the Shalco switch.

Not difficult at all. Especially if you're going so far as to hog your chassis out of solid aluminum billets. Could have actually saved a bit of machining by making two compartments separated by a bulkhead that could have been used for mounting the switch and attenuators.

se
 
There is a time and a place for two-tone

I'm sorry, it's just when I see a knob like that, I get all Siemens and die-cast magnesium alloy aroused.
What to say, those nazi inbreeding residuals remain hard to shunt.

What's that 1:5'r, a Cinemag 10C half-off ?

(more of an extension shaft type myself)
 

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I'm sorry, it's just when I see a knob like that, I get all Siemens and die-cast magnesium alloy aroused.
What to say, those nazi inbreeding residuals remain hard to shunt.

:D

What's that 1:5'r, a Cinemag 10C half-off ?

Nah. 5C at full price. The 10C doesn't do well with 2 VRMS. Though we'll offer some 1:10's for those who are using phono stages with lower output levels.

(more of an extension shaft type myself)

Thought so. I can tell by that smile on your face.

As for the Haufe's, near as I can tell, the highest level either of the two you referenced is just 0.5 volts. Much too low.

se
 

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Much too low.

My wild imagination figured like both those types at the inputs, SE buffer, bump it up with the 1:20 Cinemag, SE buffer again, loose some RIAA pounds, and finish with a buffer grand-plié.
Too low for a multi-stage transformer/buffer pre-pre for low+high output MC, bummer.

(The blue binding posts look pretty, but Hey, blue is always pretty. As goodlooking as Resista mk3, not like that MRS25 green, yuk)
 
My wild imagination figured like both those types at the inputs, SE buffer, bump it up with the 1:20 Cinemag, SE buffer again, loose some RIAA pounds, and finish with a buffer grand-plié.
Too low for a multi-stage transformer/buffer pre-pre for low+high output MC, bummer.

Haven't really thought through a phono stage. But yeah, I think it would start to get a bit messy trying to get that much gain just using transformers and buffers. I'm thinking at best you would need a high gain MC step-up trannie, feeding a buffer that took care of one half of of the RIAA curve, into another fairly high gain trannie followed by a buffer taking care of the other half of the RIAA curve, then into something like a 10C, followed by a buffer that drove an output transformer set up as a 1:2 in order to double all the stuff that you did upstream.

That's four transformers and three buffers. A but much even for a transformer lover like myself.

(The blue binding posts look pretty, but Hey, blue is always pretty. As goodlooking as Resista mk3, not like that MRS25 green, yuk)

Blue binding posts? You mean the black ones that I photographed under a blue sky and a blue patio umbrella?

se
 
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