ours sound like the 2*5*2*0?

For obvious reasons, no one is saying wether their op-amp designs are based on any particular other one that we all want that are in nice blue boxes. I'm trying to figure out which one will give me that sound.

Maybe someone could PM me with the info I need?

I've seen some "clone" designs, but not yet have I seen a layout for it.

Thanks,
Joel

PS-It's a shame that you can't just buy these from the company without having owned them in the past-if you ask me, that is what is causing this need for a lot of people to make their own.

Hey Joel,
If I were you, I would get John Hardys opamps anyways. I think they sound better and are even cheaper than A*P*I if you could buy them..
I think they go for about $50..
peace
Gil

Yeah, I've heard great things about those. I'm interested in trying to roll my own, however-for now. It'd be a lot cheaper for me-and more learning which I really need.

Joel

Check with Fabio... he has 2 252O layouts.

http://www.thediypill.phx.com.br/forumfiles/

Cheers! :guinness:

He has schematics, but no layouts posted right?

Joel

I don't think I'm ready to try and lay out my own op-amp from a schematic. :?

[quote author="babyhead"]Check with Fabio... he has 2 252O layouts.[/quote]

Where, exactly? Couldn't find them :?

Doesn't Fabio sell boards for this anyway? Jump in anytime, Bauman... :grin:

Peace,
Al.

Yeah-

That's just all of the info. Bauman sells the DOA boards with his 312 kits. I'm sure he's sitting on a stack of little boards.

:guinness:

He has schematics, but no layouts posted right?

Joel

Click to expand...

Pure lack of time Joel, I´ll try to do it soon.

I had shipped lots of it along with the R312 boards. The plan was to have people all around testing and giving opinion on how far or near we are from the originals, as I don´t have any original here. So yea, I still have some, like 300 or so, but about 1000 melcors I guess That´s why everybody that got R312 got Melcors...


2.5.2.0BC R1 on the right
A2520 on the left, my own double layer layout for 2.5.2.0

This 2.5.2.0BC is stable and sounds good right now. The only change from the schemo is C5 = 10pF instead of 47pF...


cheers!
Fabio

You're doing great work fabio, I know you're busy. ...

Let us know when you get the time to post a pcb and layout...

Cheers,
Joel

Ok let´s do this: I´ll post this 2 , PP2.5.2.0 and 2.5.2.0.BC R1...

Gimme some minutes... or I´ll forget this and ya know...

I still haven;t built Fabios boards yet...still trying to figure out how to handle matching the transistors, but as far as I know the closest thing to a real 2-5-2-0 in a pre-made package is the SC25.

I have the SC25s running next to real 2520s (cir. 1973) and as close as they are I am preferring the SC25s lately. they sound remarkably the same except for a tad more focused high end in the SC25.

The Hardy and Avedis 2520s aren't really 2520 clones. They sound much different.

Shane

OK, here it is:

http://www.thediypill.phx.com.br/forumfiles

look for:

lay_parts_*.pdf
lay_solder_*.pdf

:guinness: :guinness: :guinness:
Fabio

Some people are using the new dual matched pair in the single pack for the input. Thermal coupled and all that good stuff. Saves a little matching time.

Don't remember the p/n.

Saves a little matching time.

Click to expand...

That´s not that little btw... pls CJ try to recall that!!

cheers!
Fabio

CJ . . .


what dual matched pair is that?


Andy P

It's in a thread around here somewhere, Forrsell or Hardy might have mentioned it. Someone with a brain will step in I hope.

I'm not sure I guess you could use the LM394...which is what the Hardy 990 uses. Its essentially 25 paralled transistors per side. I think its very low current and voltage noise.

Not sure if it would sound very 2*5*2*0 though.

Other duals I'm not sure of......but THAT have some transistor arrays in 8-pin DIP package. Maybe not worth it for the 2*5*2*0 - may as well design a new gain block.

Those two would also require a new PCB layout - so they can't be what CJ is thinking of.

Hey Fabio, looks cool! Have you compared the sound of the Melcors to the A*P*I? I'm interested in that - I have a load of 1*7*3*1' PCBs that I want to use at some point.

Cheers Tom

You rock Fabio!

Thanks.

Joel

Hey Fabio, looks cool! Have you compared the sound of the Melcors to the A*P*I? I'm interested in that - I have a load of 1*7*3*1' PCBs that I want to use at some point.

Click to expand...

Yes, the only comparison I did til now. This is very hard to describe it, as usual. Lets say the Melcor sounds to me more OLD and mellow, it smooth the sound. The 2.5.2.0 sounds a lot more in-your-face and the hi end has a lot more definition, more aggressive stuff for sure...

Anyway, someday I´ll learn how to do this kind of comment, but is something like this. :roll:

:guinness:
Fabio

Nice one - from your description it sounds like I will be really happy with the Melcors, smooth and mellow is just what I like......



Cheers Tom