(re)searching for a better preamp

[jaudio]

Good

I have all the parts.

 

[rudi]

Re: Re: Re: Re: Re: Some considerations for the R&D team

Hey, I am a friend, but I'm not willing to discuss all this anymore, it's more problems for granted.
I've been there, done that, it isn't worth it.

You have the values that I recommend for the LM317/337 regs, it works, be happy with this. Use them.

I'm just going to tell you the obvious (or should be by now): you've lowered the (high) impedance of your PSU, where it matters the most.

PS: you should be using a ferrite ring around the mains cable near the trafo (I always do), probably it solves your problem with that electric fence.
And twist the wires.

Carlos I understand 100% i was just pulling your leg, I wouldn't want to discuss it aswell after all the hype 😉

well you gave me the answer i was looking for. 😀 now i will take it to my engineer friends.....this will baffle them once again, they will ague it and then I can show them in practice. (i am putting in a jumper on the board to amke the change easily)

I have a few ferrites lying around. I will try it....

thanks very much

 

[rudi]

Is that good?
That's what I wanted to avoid...

well ............it is good. what happened is that it is perfect with a OPA627 but you can mess it up with anything else. 😀

but seriously, it still sound like before but with a touch of the OPA627 signature. try it, it is actaully very nice. but at the end of the day it all down to personal taste again.

but I will build another one with your pre layout and a identical power supply to the WJ and then I will be able to judge it better. the track length, components and everything else is the same except for the routing

 

[filholder]

Thanls Rudi,

I'll give it a go when thing at work get a little bit less crazy, 16 hrs days at th moment.

Thanks for the values, i look foward to trying it our.

Phil

 

[float]

Thanks George, j, Rudi,
I didn't really think about bending pins, but as there's only 8 that matter, I'm sure I'll make it fit.

Sorry about asking a question and then disappearing all day - damn work!😡

 

[filholder]

HI,

How crucial is the quailty of the cap on the snubber?

The only 22uf caps i can find are currently attached to a network card...

would this be good enough to hear the benifit?


phil

they measure bang on 22 so they cant be too bad i guess

wendell 105c 25v, are these utter cr@p or ok?

 

[carlosfm]

HI,
How crucial is the quailty of the cap on the snubber?

The only 22uf caps i can find are currently attached to a network card...

would this be good enough to hear the benifit?
phil

Huh... try it.
I'm out of time to test brands of caps on the snubber
I don't have anything nasty on my parts box, I'm very picky when buying caps.
No need to spend a fortune, Philips/BC 037 does it for me.
No green Lelon caps, please.

 

[filholder]

havent got any .47 ohm resistors either

 

[rudi]

havent got any .47 ohm resistors either

you have to innovative. 2x 1R in parallel and so on.

 

[filholder]

Yeah, true but the only 1R resistors i had were 3 watt ones and i didnt have enough space.

I'll go out and get some caps and resistor at lunch time.

Cheers guys

 

[carlosfm]

I'll go out and get some caps and resistor at lunch time.

Cheers guys

Good idea. 😉

 

[Nuuk]

Good idea.

Not if you live where I do!

 

[jaudio]

Hello Rudi

How much capacitance do you have in front of the first regulators?

 

[rudi]

13200uf per rail

4 x 3300

 

[filholder]

Well thats was a bit of a good trip to maplin, got all i wanted and the capacitor lucky bags which sell for a £2.99 had loads of oscons in. Got 3 packs!!!

ill give it a go tonight

 

[carlosfm]

Not if you live where I do!

I'm already happy that I don't step on Rudi's electrified fence. 😀 😀 😀

 

[LTK]

Hey Carlos, I wish you could hear this AvondaleNCC200 used with the AD815 😱 I've never had dynamics like this in my front room before, its CRAZY! it does sound very good with any of my other amps but its bloody explosive with this one😀
I need a bigger room the IPL's love this power
Can't wait to get the AD815AY built

 

[carlosfm]

Explosive, yes Leo I would discribe the AD815 preamp just like that! 😎

It just gives you the sense that you've been missing what's on a (good) recording, that every other pre doesn't cope with that.

 

[LTK]

I've been listening to Morphine and Blue man group, the bass on some of the tracks FEEL nice😀
I've tried other pre-amps that do sound good, some obviously better than others but none seem to give the control of the AD815, when you say it gives you a sense of whats been missing I understand what you mean😎
I've still got a tube pre to try out at some stage so I'll look forward to see how it compares.

Another thing which I'm sure will make peoples eyes roll is the snubber, I did a hear a difference using them on the chip amps etc but this one after the regulator makes a very noticeable difference, I've been comparing it with and without and its obvious this thing does improve the sound especially in my system
Anyway, I won't mention the snubber again seeing as though it can cause moaning😉

 

[carlosfm]

I've been listening to Morphine...

Man, I love Morphine.

Another thing which I'm sure will make peoples eyes roll is the snubber, I did a hear a difference using them on the chip amps etc but this one after the regulator makes a very noticeable difference, I've been comparing it with and without and its obvious this thing does improve the sound especially in my system
Anyway, I won't mention the snubber again seeing as though it can cause moaning😉

Moaning, ehh? 😀 😀 😀