New Burr Brown based preamp, under $190...

  • Thread starter Thread starter tubedude
  • Start date Start date
tubedude

tubedude

New member
Now, I know its a Rane, but if they designed it right, and its a fairly simple basic design, then this could be a killer little preamp for the $160 range.
The Sytek and Grace 101 preamps are Burr Brown based preamps, as well as the new Studio Projects preamp that is about to be released. The Sytek and Grace are pretty respected preamps, especially the Sytek.

Here it is... http://www.rane.com/ms1b.html

Anyone heard this thing or anything about it yet? Anyone have one? If you know schematics, they are there also, so take a loko and see if it appears to be a good design.
I may order one from Full Compass tomrrow just to check it out. Cheap enough I guess, always send it back if it blows chunks.
Peace!
 
What? Has this been discussed already? If so, a search on ms1b didnt turn up anything.
What do you mean?
 
I found this off a web search. Interesting stuff:

http://users.erols.com/schum-buss/PDFS/Docs/ms1b_ana.pdf

Simply having a burr-brown isn't necessarily going to make something good. A BB opamp is pretty inexpensive to attain. You can replace the opamp of a lot of pres for a bb; if you have an art tube mp lying around, that's actually a good candidate.

A really good idea is to get a used symetrix pre and swap whatever is in there for a bb. Ditto for a presonus.
 
Last time I priced it out the TI (burr brown) opamps often recommended to replace the ops in the SX202 were like $9 each.

I've been thinking about it because on its own, the SX202 sounds like shit.

Slackmaster 2000
 
Call Texas Instruments and tell them you're designing a new mic pre that will likely top at least 100K units in the first year of production. ;) They'll send you as many as you want (within reason) for free.
 
Never said BB's would make it good, just that if designed properly, it has much potential and is worth looking in to.
Simply swapping the op-amp is NOT a good idea in most cases since the requirments are different with every opamp and could cuase ocillation problems. The Burrs areNOT used often becuase of the price, which IS expenzive to most manufacturers trying to put out a cheap product.

They sell for $144, plus shipping. Worth looking into, I think. Never know.
 
The schematics are the main reason I like Rane. Makes it easy to modify their stuff. :)

Rane designs are very conservative and respectable. I never argue much with their designs, but sometimes their component choices aren’t the greatest. For example, I don’t like the electrolytic caps C1 and C2 in the signal path. I would shunt those with some polys.

barefoot
 
So with a few modifications, this thing could probably amount to a real clean, no-frills pre is what I gather? Hmmm . . .
 
Looks like it. The +-15V power supply is going to always limit its ability to easily handle very hot signals. So, it could never be considered a "high performance" preamp. But the noise and gain linearity specs on the BB look pretty good within it's range.

Yeah, should work as a nice clean linear pre as long as you don’t drive it too hard. Don’t expect it to add any "character" to the sound though.

barefoot
 
barefoot said:
Looks like it. The +-15V power supply is going to always limit its ability to easily handle very hot signals.
Click to expand...

Interesting. Sorry to keep buggin' you, but how does that work? Does greater power supply = more headroom? Quicker transient response (higher slew)? Neither?

:D Thanks.
 
chessrock said:
...Does greater power supply = more headroom? Quicker transient response (higher slew)?...
Click to expand...
Both.

Of course, a wider supply voltage gives more headroom - pretty obvious. The thing that’s not obvious, however, is its effect on the tradeoff between gain linearity and bandwidth. Linear gain means that if you multiply the signal by 100 (+40dB gain), for example, then ALL of the signal is amplified by that much throughout the entire dynamic range - the very quite and very loud parts are treated the same. Achieving linear gain across a large dynamic range forces you to limit the bandwidth of the circuit. Likewise, wide bandwidth (high slew) circuits will necessarily have a gain versus input amplitude curve rather than a flat line.

For reasons which I would have to go back to my text books to explain, you can get around this gain linearity versus bandwidth issue somewhat by increasing the supply voltage….. BUT…. there are tradeoffs. There are always tradeoffs.:) The major performance tradeoff is noise. Increasing the supply voltage increases the noise floor (generally current induced noise). This is usually a favorable tradeoff because signal distortion is much more offensive than simple added noise. The major practical tradeoff is cost. Lower cost integrated amplifiers just aren’t made for supplies above 18V. So you’re forced to build discrete circuits. Then you get into the issues of matching components, thermal tracking, etc. – things achieved far more inexpensively and efficiently on a monolithic silicon chip. Plus, higher voltage supplies also require discrete regulation circuits and therefore, are also more expensive.

barefoot
 
tubedude said:
Now, I know its a Rane, but if they designed it right, and its a fairly simple basic design, then this could be a killer little preamp for the $160 range.
Cheap enough I guess, always send it back if it blows chunks.
Peace!
Click to expand...

Looks more like a contractor unit. Not many features, but enough for a fixed installation. Hell, it may sound ok, but who knows how it was built. Let us know how it sounds.
 
Just talked to a friend who thinks higher voltage designs may actually have LESS noise associated with them. The main drawbacks are cost, like I said, and higher power consumption. So, I’m not certain about this point now. We need a real EE to answer this question.

In any case the headroom and gain linearity do go up, so the advantages are clear from that perspective alone.

barefoot
 
Hi barefoot.... you might find something here

http://www.jensen-transformers.com/apps_wp.html

Jensen 990 OP was seen as one oif the best mic-amps made about 20 years ago, it's is based around the same ideas that gave one of gratest sounding consoles ever built, the all american API.
lot of infos of pre's in here, they are running +-24, wich was cvommon among the real hi-end units.

rgds
 
Thanks rambo.:) Yeah, I'm familiar the information on the Jensen site.

barefoot
 
Tube,

I forgot to mention... The Grace and Sytek preamps you mentioned might be using the INA103 chip. It’s the higher performance 'big brother' of the INA106 used in the Rane.

barefoot
 
You must log in or register to reply here.
Back
Top