high quality transparent micpre diy?

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

salomonander

Well-known member
Joined
Aug 28, 2011
Messages
913
Hey
im in need of a really good and transparent micpre. id like to build something instead of buying in the shop. is there any projects that can hold up to the quality of gml, gordon and forssell preamps?  thanks

ps: i have seen that forssell has some schematics on his page. is the one used for his smp-2 on there? if yes, which on is it?
 
hey
thanks. how about a hardy m1 clone? which route could i take there? i have seen some boards from jlm if im correct.
 
I wouldn't really call that transparent then. DOAs are good for color, driving large currents and being bad-ass... Not really good at leaving your signal untouched.
 
salomonander said:
im looking for something with discrete opamps. thanks so far.

I thought you said transparent...  ;D

There are a number of modern off the shelf solutions that are more linear, than "name" preamps.

Discrete opamps when very well done can approach these modern IC solutions.


JR
 
DOAs are good for color, driving large currents and being bad-ass...

I've designed discrete opamps which outperform available IC chips regarding objective performance by a large margin. It's not the fundamental technology that counts, it's the overall circuit behaviour and thus achieved performance.

My "Monte Generoso" mic preamp (www.sg-acoustics.ch/analogue_audio/microphone_preamplifiers/) is probably one of the objectively best performing DIY mic preamps currently available.

Samuel
 
I realize that DOAs can be designed to be uber clean, I was commenting on more the variety that are pined over in these forums. (2520, 990, etc.) These are not super opamps. I made a generalized statement, sorry to lop your works in with that. They're quite the cut above.
 
how much you wanna spend on transformers?

Hardy uses a Jensen output that can run you into some serious coin just for 1 part,

Quad 8 might also be considered, you can get the original cards off evilbay fro the price of a full tank of gas,
 
salomonander said:
im in need of a really good and transparent micpre. id like to build something instead of buying in the shop. is there any projects that can hold up to the quality of gml, gordon and forssell preamps?
With a transparent micpre (maybe acrylic) you'll probably miss the shielding of the metal enclosure that for usual is not transparent.
Neither the gml nor the gordon or forsell are transparent micpres. They only might sound transparent.
;D ::)
 
Harpo said:
.....
With a transparent micpre (maybe acrylic) you'll probably miss the shielding of the metal enclosure that for usual is not transparent.
Neither the gml nor the gordon or forsell are transparent micpres. They only might sound transparent.
.....
Objection! That's pure BS. You can always use a wire mesh, it somewhat shields and is somehow transparent. Ssssoo, no more excuses ...
fishnet_stockings.jpg
 
hey guys

thanks for the replies. im not a designer myself. but the forssell, gml and gordon i have used and i find them very transparent - or just right for my needs. so maybe i dont mean ueber transparent but just clean and not overly coloured :) what i have in the studio now are mainly neves and old telefunken tube preamps. i need something more natural to complement them. i dont mind spending "big" money on jensen transformers. as long as it gets me in the gml/forssell ballpark of quality.
 
you might consider a tube amp,  there is a WeCo one tube mic preamp in the rack that is pre that is, well, transparent is not really a good word for a mic pre, detailed might be a more apt description,

the Gordon is nice, has that external pwr supply which is very helpful with the low level signa, put out by most mics, and you gotta love the teflon PC board, not really DIY friendly nor cheap,

Valley People has a mic pre that is the only one i know of without an input transformer, this can led to more detail if you can get the output stage to behave in a nice way,





 
Samuel Groner said:
DOAs are good for color, driving large currents and being bad-ass...

I've designed discrete opamps which outperform available IC chips regarding objective performance by a large margin. It's not the fundamental technology that counts, it's the overall circuit behaviour and thus achieved performance.

My "Monte Generoso" mic preamp (www.sg-acoustics.ch/analogue_audio/microphone_preamplifiers/) is probably one of the objectively best performing DIY mic preamps currently available.

Samuel
As usual, nice work... anyone interested in discrete design would be well advised to study your work.

I hope you will flesh this out into a full form text book with detailed discussion describing the sundry designs so students and those wanting to increase their understanding can follow along (and you might make a few Euros for your effort.)

My only quibble is the subjective "large margin" qualifier for objective improvement. I have been in the trenches listening to advertising claims about huge improvements in S/N or linearity of mic preamps for decades while we have been close to theoretical performance for a few decades. I concede my "close to" is also subjective. My criteria is clearly audible differences.  I don't doubt that you can beat ICs in several areas on the bench. This "large margin" may depend on whether you are comparing to distance from 0% or distance from 100%.
 
Again great stuff.... better is always better, unless time and money counts too. but better is still worth academic pursuit.

JR

PS: The use of an inductor between the input LTP (after Jensen) has not yet been replicated in silicon, while never say never. I've pondered a gyrator like cap + active component to mimic an inductance, but it seems like the input LTP is the wrong place to add complexity (and noise).
 
i want to advise the 500 series lola preamp. never heard such a transparent and clear preamp (transparent in a positive way). very good/fast transient respond and shiny high frequency... it makes you feel being so close to real source.
 

Latest posts

Back
Top