|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
98.149.128.193
You know those cheap (in their day) chrome mono and stereo preamps Lafayette sold in the 70s. Just a chassis with power transformer, 12AX7, and a big filter cap. My old early 70s Lafayette catalog shows them for $7 to $10.
These things fetch a fortune on Ebay and Audiogon - I have seen them go for over $200. Why? These were cheap Japanese junk of the day. Very basic circuit, nothing special. No different than buying a no name tube amp from China today.
Just goes to show the gross mis-conceptions and wishful thinking in the tube world!
Follow Ups:
I would think a little loss of gain to cathode bias the input stage would help things out a bit- allowing you to direct couple the input.
Getting it to have accurate RIAA shouldn't be a problem.
Might be nice in a bedroom system...
Over the years I followed Interstage Tranny's posts about the "chrome cuties" and wondered if I he could be on to something. However I couldn't bring myself to buy a Lafayette or Shure M65 so I just built one using the same circuit and the same upgraded parts I would have used if I had refurbished a chrome cutie. The bottom line: the M65 circuit is actually a pretty decent sounding preamp even if it wasn't good enough to replace my regular phono stage.Nevertheless, I think it's fair to say some of the "cheap" aspects of the Lafayette and Shure preamps may actually contribute to their sound quality. These include the AC supply for the 12ax7 heaters. Yes, there is some hum compared to a DC supply but in my experience running heaters with AC usually sounds better than DC. Another factor is the carbon comp resistors used throughout. Yes, they can be noisy and go out of tolerance but they also have a warm, dynamic, musical sound quality.
Anyway, I would just say the chrome cuties deserve their reputation as an inexpensive but musical phono option.
Edits: 08/08/21
He says, "I believe these sensibly modified chrome cutie phono preamps could be the best budget phono stage available; especially if you can DIY"
Below is a link to one he refurbished, but there are other posts as well. Just search "Chrome Cutie" (mostly in DIY/Tube) if you're interested.
Maybe it's part nostalgia, where it was someone's first phono set-up, combined with the idea that they can be greatly improved with some careful work.
It's probably wiser than some of these current production inexpensive "tube" phono stages where the tubes are used as buffers and pretty lights, while all the heavy lifting is done via op-amps.
OK, so some modify this product even to the point of gutting it and building a different circuit design.
Well then it's no longer the same product! If I build out a Marantz model 7 phono preamp in a Lafayette chassis, it's now a Marantz 7 clone, not a cheap 70s Japanese product. If you are going to do that, why buy these low quality preamps at inflated prices? Why not just buy new components and build what you really want for equal or more likely far less in cost.
Think about it, what can you salvage? The power transformer and possibly a vintage 12AX7 that might have some life left. The rest is scrapped. That transformer is less than $20 new at Allied. Ok you got the chassis but with the money saved you could not only buy a blank Hammond chassis, but also the tools, drill, step bit, to work the blank chassis and not be restricted to the old component placements.
Like I said I just don't get it. This seems like the true objective is nostalgia. And that's fine. But lets not get lost in fantasy that these are some high end tube glory era phono preamp. Just look at the schematic Eli posted. That's a "Mad Man Muntz" design. Only include enough components to get a signal through, nothing more. And if that's even close to true RIAA or NAB equalization, I'll be a monkey's uncle!
What millennial could be bothered to buy a blank chassis and build a preamp in it? That's way too much time and effort. Besides, how could such a creation ever compare with the improvement in sound that comes from a preamp and all its components being 60 years old?
--------------------------
Buy Chinese. Bury freedom.
Opinions,everybody has them. However, the only opinion that matters is mine! ;> D
Like all "simple" 'X7 setups, the "Chrome Cutie" can't fight its way out of a wet paper bag.
The debate of active vs. passive EQ will never end. A clear thing is that passive topology is more overload resistant. Active EQ makes changing between RIAA (phono) and NAB (tape) easier. Fisher did the same thing in a GE style 6SC7 based unit.
Squeezing the max. possible out of a stock "Chrome Cutie" requires genuine 7025 equivalents, like the Sovtek 12AX7LPS. AC heating is employed.
IMO, an obvious tweak is full wave bridge rectification of the B+ supply using modern quiet diodes.
BTW, opamp phono preamps can be good. See Jim Hagerman's "Bugle". I agree with 'shovel that the hybrid baloney should be passed by.
Eli D.
Thanks for the morning laugh, Eli!
I bought a one of those little chrome phono stages for $1, years ago, mostly for the two 12AX7s. But the chroming was top-notch, so I always used it as a decoration. With Gusser making me aware that they're going for $200, maybe it's time to sell mine. I've got enough projects.
"BTW, opamp phono preamps can be good" . You'll get no argument from me on that topic. I have several of them, including a Graham Slee Reflex, and the DIY LR (no capacitors in the signal path) developed by Pete Millett. I'm sure you're familiar with Pete, as he used to be quite active and innovative with tube circuit design over on Tube DIY Asylum. Regarding his LR phono, Pete said:
"Recently, after listening to it [the LR phono] compared to a couple of different tube and hybrid preamps (some of which I designed), I came to the conclusion that the solid-state LR unit sounded better than the others."
As for the hybrid designs, having never heard one, I can't comment on the sonics, which may be quite good for the money spent. My comment was geared more towards unsuspecting purchasers who aren't getting what they think they're getting, with regard to the function of the tubes.
"As for the hybrid designs, having never heard one, I can't comment on the sonics, which may be quite good for the money spent."
The tweaked RCA setup I'm associated with is a hybrid. However, all voltage amplification is "hollow state". FETs make excellent voltage followers (buffers) and even a wimp, like the 'X7 triode, has no problem coping with the tiny capacitances of the ZVN0545A .
Eli D.
... I immediately thought of a commercial 'opamps with tube buffers' design.
I've heard good things about the Duttman/RCA phono from someone who built one. Of course now TK is going to tell me I need an exorcism, and he's probably right. But in my case it has little to do with sand in the signal path.
Eli D.
--------------------------
Buy Chinese. Bury freedom.
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: