I did that; and it really sounded clean and toobey. Even though output transistors (well, at least some of them) worked in class C.
Fast wideband response, absence of srossover distortions, and graceful clipping is the way to go.
Given what I suspect was the intent of the original designers, I don't believe this would be perceived as a design mistake. I'm quite sure it was deliberate and to a specific end sonically speaking. It is what I call a "tone control" - tongue in cheek..
SY's comment in a previous post about high end audio was pretty much spot on in my experience. (Largely negative..)
Ahhh; it was designed by professionals?
I was wrong in such case. Horrible design.
I thought it was design of some novice who is trying to learn...
Perhaps not quite.. See Black Dahlia | A Day Without Music Is Like a Black and White Sunset
Here's an update to the design: Tip_73
Original article: http://www.enjoythemusic.com/magazine/equipment/1103/midmonth/bluevelvet.htm
His speakers are highly regarded. The pre-amplifier will have to stand on its own merits. To be fair I have not heard one, but I'd imagine it sounds at least OK. The design philosophy overall is not one I would espouse..
The second stage inverting amplifier configuration is clever though.. Something I should have mentioned before.
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I think you will enjoy it.. I am always surprised at how good it sounds when I hook one up as a stand in when I am working on the 26 dht based line stage I normally use.
Would you be interested in the relatively simple regulated B+ supply that I usually use with this design? If so I can draw it up and post it here sometime in the next day or so..
Hi kevinkr, please do. However, I will be building it with parts I already have...like hammond trafos, caps, and so on, so I may not be fully following it. Anyway, I want to use DC on heaters, one DC regulator per side, I may even built is as two mono blocks, as I have mono block power amplifiers...will see. I already have 6SN7s, I like to stick to these as I have build headphone amp with these and I love the sound.
Hi kevinkr,
I just finished your trendy SRPP line stage and hooked it up to the EL34 of simple SE as the driver stage. Sounds great. However, has little low gain (20) for me in comparison to Tubelabs Simple SE driver stage (50).
Any idea how the gain of trendy SRPP can be boosted a little?
Ed
I just finished your trendy SRPP line stage and hooked it up to the EL34 of simple SE as the driver stage. Sounds great. However, has little low gain (20) for me in comparison to Tubelabs Simple SE driver stage (50).
Any idea how the gain of trendy SRPP can be boosted a little?
Ed
Hmm....
You gotta Larf.....
They come up with what seems to be a unanimously mediocre and even Poor design.....
Then in the Text that goes with it, extrolls the virtues of certain type Audiofool capacitors!
Unbelievable! What a load of old guff!
This was designed by a Professional Co....?
In that case, there's hope for me yet!
You gotta Larf.....
They come up with what seems to be a unanimously mediocre and even Poor design.....
Then in the Text that goes with it, extrolls the virtues of certain type Audiofool capacitors!
Unbelievable! What a load of old guff!
This was designed by a Professional Co....?
In that case, there's hope for me yet!
It doesn't appear that any of the previous posters actually built a Blue Velvet. I built one back when the article first appeared, and I followed Olsher's circuit and part recommendations pretty closely with one exception---I didn't use his Gas Tube regulator. In any event, the preamp sounded pretty much as prior posters speculated it might. It's dark and heavy, lacking in life. It is a mediocre design. The only mystery to me is why Kara Chafee is associated with it. I would have expected her to suggest better ways of altering the design. I suspect her input on the design was very minor.
Dave
Dave
zombie preamp thread
I don't need more gain but I'd like to replace my 12au7 (Bruce Rosenblit ) SRPP with something a little simpler than an Olsen Raven
SRPP 6SN7 (or similar) with gas regulated P/S will do. I need to drive some current so plain resitor loading is out.
Unless someone has a sensiblely priced 10mA linedriving transformer (Lundall are wonderful but..)
Maybe 5687 with 15mA/50V and 15K of resistor (or CSS)?
I don't need more gain but I'd like to replace my 12au7 (Bruce Rosenblit ) SRPP with something a little simpler than an Olsen Raven
SRPP 6SN7 (or similar) with gas regulated P/S will do. I need to drive some current so plain resitor loading is out.
Unless someone has a sensiblely priced 10mA linedriving transformer (Lundall are wonderful but..)
Maybe 5687 with 15mA/50V and 15K of resistor (or CSS)?
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The Poor mans raven is a simple build really - but not to everyones taste.
A 5687 with a simple CCS plate load will provide excellent performance (much better than the Blue Velvet discussed here). A IXCP10M45 will do a fine job for small money.
Shoog
Thanks Shoog
I'll get "round to" a PMR (or not-so-PMR) eventually but as you've pointed out, there's a fair bit of parts trialling and circuit fettling to get decent performance.
Thanks for that suggestion - looks like the go. Just got to find some...
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