PlanetZ forums - scopeusers.com

Greetings all. just purchased a focusrite isa one pre mic amp and trying to link the 9 Pin AES/SPDIF Pin-Out with the SPDIF Pin-In on the pulsar 1 card .No Go.tried making the pulsar the slave and vice a versa on the focusrite.At the moment I am Only using the analogue connections (still sounds great) but would like a solution to this so i can use the benefits of the A/D converter.My ? is ,Does scope make any hardware or software to rectify this problem or am i doing something wrong with the setup? Many thanks ,Al ditrich

I think you'll need a syncplate because there's no wordclock on a pulsar1-card.

Grtz

you might find sp/dif lightpipe easier to use. you will need some kind of custom cable for the 9 pin. the 9 pin connector is for an 8 channel digital snake. i can't really tell from the info on the site, but i would expect that with the one channel pre, only the first channels pins as shown on the wiring diagram would be active, since they seem to use the same ad/da card with the 8 channel pre.

unless you have a bnc wordclock card for your pulsar, you'll need to slave it to the focusrite, as the focusrite only has bnc sync input(there's no aes/ebu or sp/dif input, right?).

I wouldn't expect a high quality converter inside the Focusrite anyway - it's their budget line.

cheers, Tom

Thank you very much for the valuable info .Yes i dont have a aes/spdif -in on the focusrite,I try going for the sync plate and hopefully it will get me a cleaner sound .One can only wish!

I don't deal very much with micpres, but remember a discussion in an audio shop recently.
He had a Neve Portico, UAD Twinfinity, Telefunken 672, Lawo and that Focusrite.
Bottomline was the stunning quality of the Telefunken and Lawo (usually 200-400 Euro on eBay).
They were at least on par with the Neve (as a matter of taste might as well beat it, no kidding), the UAD was in no way up to the challenge and the seller didn't even mention the Focusrite.
(We were switching the units to A/B with different mics including ribbons)

I don't claim to be a mic pre expert, but I have some experience with old german broadcast stuff, some devices serve as perfect DIs for electric guitar and bass (with a definition you expect from Avalon or Millenia, but for a fraction of the cost).

The Telefunken 672 is a universal design which gets it's final function by bridges and resistors on the output connector, V376 and V676 is a plain micpre with dials for gain etc.
These are among the best designs worldwide - if you provide 24V power and some connectors yourself there is NOTHING that can beat them for the bucks.
You just have to be careful to pick the discrete versions with single transistors.
Later releases have been built with ICs, best if there's a picture of the internal circuit board - a serious seller WILL provide that. Others try to hide the ICs on photos by shooting from specific angles...
There's tons of information about that stuff on the net, even circuit diagrams if you know where to look. Here's a comment from gearslutz, but you'll find lots of similiar praises.
(to be honest I totally love that fat, yet transparent and defined tone - I often play bass just through such a device and it still kicks me after > 1 year of usage)

cheers, Tom

Thanks Tom .ill follow your info up .sounds great.Al Ditrich

sorry, I could have posted this pic of a V672 before...
this thread has a nice pic of a Siemens V276 and some info. Notice there are no pots but a switching resistor cascade.
The numbering can be confusing...
it is according to German broadcast specs layed out in the so called Brown Book (Braunbuch) named after it's cover color.
This extremely detailed and systematic description of requirements was the base of contracts with gear suppliers.
Broadcast was a government item back then... and money didn't matter at all. In one of the threads it's mentioned that the Siemens Pre was about $900 in 1965. A huge amount of cash...

One thing worth mentioning is the very low output impedance of such modules in the 16-32 Ohm range.
This has been reported to conflict sometimes with modern > 10k input designs due to the transformer inductance giving an unpleasant high mid emphasis.

In my setup I didn't notice this - just the slight signal degradation you'd expect from double conversion.
As mentioned my 'DI' accepts a headphone directly.
Monitored 'after' Scope, the signal looses a tiny bit of smoothness and definition, as it passes 2 opamp stages during conversion and 2 in the headphone amp.

cheers, Tom