High-end preamp for my GC

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peranders said:
Carlos, you haven't thought about driving the cable with the same source impedance as the cable? I see that you are near that. Why don't you test 50 ohms out, 50 ohms cable and last 50 ohms load? (or the impedance you have)


I may try that, I think I still have some RG58 "10Base2" 50 ohm network cable in my basement, from my hardware days.:dodgy:
 
carlosfm said:



What speaker cable?
My speaker cable is Kimber 4TC...
I was referring to the interconnect cable that is soldered to the preamp board on the picture.
Anyway, I have Cat.5 as speaker cable on one of my systems and I think it's very good.
A cable that transmits very high frequencies over a 100-120m distance has to be good.
Did you know that a cable, to be Cat.5 (that's a norm), has to use high-purity OFC copper?
Yes, it's OFC copper.

Hi, Carlosfm,
Why don't you both try using ANY cable and cable compensation circuit /electronics/ - this requires only a single op-amp and a few passives and is better to integrate in the power amp.

:idea: :bulb:
 
(after one evening plenty of beer)
A paint? no thanks, it's too much, maybe a half-paint...;)

Sorry for the joke, Carlos, but this stage we have fitted a lot of components in the signal path!!I don't see them but there are a lot inside !!

Anyway, I agree with you in that the lesser components outside the chips are preffered.

By the way, I already have the buf and the opa, so I will try soon. Which trafo are you using?
 
Raka said:
(after one evening plenty of beer)
A paint? no thanks, it's too much, maybe a half-paint...;)

Sorry for the joke, Carlos, but this stage we have fitted a lot of components in the signal path!!I don't see them but there are a lot inside !!

Anyway, I agree with you in that the lesser components outside the chips are preffered.

By the way, I already have the buf and the opa, so I will try soon. Which trafo are you using?


:scratch: A paint or a pint?
Anyway, sometimes with a couple of beers even the solder flows better.:devily:

Ok, Raka, but you can't do an op-amp based preamp with much less parts than this one, only if you take the buffer out, but the buffer is a fundamental part of my pre.
I could have the power amp on the other side of the house, my pre would drive it with no problems.
Of course the op-amps have transistors inside...
What I wouldn't do is to put another op-amp after my pre, no way.

Ah, the trafo...
This gorgeous little toroid is 2x20V, and was salvaged from an old Nokia modem:devily: , from the days when those things were very expensive, but very well built.
My PSU is stabilized at +/- 18 volts.
 
Raka said:
Carlos
Thanks for the info. As soon as I get the trafo I'm trying a pre like yours.


Hey Raka, one thing at each time.
I'm still waiting to hear your impressions about the OPA2228 on your phono preamp.:rolleyes:

Anyway, tomorrow I'm going on vacancies for a week and my new contact is the Desert Island.:devily:
With some cold beer.
Two pints, please.;)
See you guys in a week.:cool:
 
LOL, I'm back!

Guys, let me tell you...
The day before going on my holidays, I've been listening to my creation.
It had been playing for a week, the Dac connected to my pre, and the cd-player in repeat.
I ejected the cd that was playing and put Diana Krall "Live in Paris".
The moment I hit play, I got :eek: :eek: :eek: :eek: :bigeyes: :bigeyes: :bigeyes: .
Wooooooooooooowwwww...
I felt like I was going to cry...
The treble was soooooo pure as I never heard in a system.
It reminds me the sound I hear when a guy is playing drums in front of me.;)
The burning-in once again proves to make difference.
This is audio nirvana, at last.
I knew I have excellent speakers (Epos 11), excellent Dac (Audio Alchemy DDE v3.0, tweaked with OPA627s and a double-regulated PSU made by me), but deam, now they're delivering.
I never thought I could have a sound like this at home, this is ultra-high-end, and I could never afford it.
That's the beauty of DIY.:nod:
 
It's a good thing to back home ;)

I usually go out at the weekend and as soon as I enter, I switch on the hifi and I think this is good...

I also have the Live in Paris, and I use this CD to check things as it seems to be a good recording. Too easy to listen to, my ears say, btw. Nice hand played guitar on track 4 (?) intro.

Do you know if your neighbors like Diana too? Maybe they don't anymore :clown:
 
Oh yes, ecstasy is the term

Nuuk said:


Welcome back Carlos, hope you had a good break!

I'm a little confused here! :confused: Did you change something in your system for it to give you this ecstatic reaction or was it just the fact that it has burned in longer?

Of course, I have that DK CD and know that also helps ;)


Hi Nuuk,
No, I didn't change absolutely anything.
And I had listened to that DK cd before, with the preamp as it is, laying on the floor, without a box, and with provisorious wiring.
But I noticed, after a week of burning-in, a widening of the soundstage and a "clean-up" of the treble, absolutely no grain, clean clean clean clean...:eek:
What was already excellent is now stratospheric.:eek:
Did the floor burn-in too?:eek: :eek: :clown:
I can't put it in words, take the first plane to Lisbon and come on, let's hear it.:cool:
I've got good beer too.;)
 
JOE DIRT® said:
Carlos I`ll be right over to drink your beer and listen to this system...hahaha

DIRT®


Come on, JOE, lol lol lol!!!
Oh, and bring one of your boxes, maby I find a good transformer for my ultra-small GC!:clown:
And I need a box too.:bawling:
I told my wife to buy a little wood box, those where women put their diamonds and pearls.:clown:
It was burning-in all the week while I was on holidays.:devily:
Let's see if I "burned-in" my bench too.:clown:
 
I built these for you Carlos...like the 100 000 cfm cooling fans???
 

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