Turtlerock Forum

I've been doing a lot of location/live stuff lately, and it looks like I will be for a few months to come, so I was thinking of getting a little location rack going.

One of the biggest problems I've been having on the location jobs I've been doing is not being able to use all my ribbon mics due to lack of gain/hiss when I'm cranking things up. I'm gonna buy a few of the FetHead thinggies and try them out, but I'd really like to build a rack of 4-8 clean, high gain pres. Think Grace Designs/AEA RPQ/Millenia etc.

A quick search of the usual DIY places came up trumps- mostly lower gain, coloured pres.

Any ideas?
In an ideal world it would be 8 pres in a 1 or 2ru unit.

DIY: Both SSL 9k and Green pres, seem to get good reviews for clean gain and there is the BAN from JLM too.

New options: DAV clean and they are also very light which is good for location stuff.

I think the Green Pre would fit this bill

Thanks guys-

I did find the Green Pre and SSL9k, but was a bit nervous as the people using the Greens were only comparing to the stock pre's in their Digi's and cheap converter boxes. The Green Pre especially get's mentioned a lot as a great 'beginner' DIY job, which made me wonder if it's popularity was more about construction ease than sound quality.
Have you used the Green Pre Nick?

I feel funny about the SSL, as it's a pre based on a console famous for everything except it's preamps! I'll have a deeper look into it though.


DAV would be ideal but I'm not sure if $ will stretch at the moment.

if you know what you're doing:

http://www.forsselltech.com/#!/articles/9

Thanks Jamil,

That looks pretty straightforward. Have you heard it?

Nope. but it's a schematic (not complete) but more hi fi than any other DIY projects??...not sure if JLM preamps suite your needs...as their transparent pre *baby animal" goes up to 60dB..perhaps too low for u.

Bugger, that Forsell looks good but I just did a bit more reading and you need to use the Forsell JMP-1 card, which is apparently no longer around.

The other pre looks ok, but I'm not sure I want transformer input and I'm unsure of gain available.

cant get second hand?

The JLM BAD http://www.jlmaudio.com/shop/index.php? ... oductId=50 gives up to 75dB of gain, but I am not sure of its transparency. Why don't you give Joe a call and ask his advice, or You could send Rob on here a PM and see what he suggests.

Not easily at least. I'll keep looking

Gian wrote:The JLM BAD http://www.jlmaudio.com/shop/index.php? ... oductId=50 gives up to 75dB of gain, but I am not sure of its transparency. Why don't you give Joe a call and ask his advice, or You could send Rob on here a PM and see what he suggests.

says "oldschool styie"....not sure that's gonna be too transparent. would sound sick tho.

Pricey, but the Dual99V in rack or 500 series gives you 75 dB http://www.jlmaudio.com/shop/index.php? ... oductId=33 and is transparent

What's your budget?

DAV electronics BG1 rack...thats transparent and last time i checked was 1065$ Aus, including shipping...
and is big sounding and transparent...

This is pretty interesting-

Supposedly the SSL, DAV and Green Pre are based around this circuit (says a few posts on Group DIY). Made by an Australian. An interesting read.

http://leonaudio.biz/cohen.htm

The Green is based around the Amek 9098 preamp, but without the output transformer.

Very clean, very quiet with a wonderful dynamic range.

Peter

peterc wrote:The Green is based around the Amek 9098 preamp, but without the output transformer.

Very clean, very quiet with a wonderful dynamic range.

Peter

First time I have heard that it was based on the Amek 9098. Are you sure that is not a net roumour to get the green a bit of legitimacy?
I too have read it was based on an SSL design.

I'm pretty sure Peter designed the Green Pre so I'll trust him if he says it is an Amek!
I'd be interested to know if the Amek is related to the "Cohen" design, I think it's around the right time frame.

Are you still selling PCB's for the Green Pre Peter?

What about JLM's BAN? That's twice I recco'd it in 2 days. I am not sponsored by Joe....

Yeah, a few JLM things are definitely on the list!
It's all coming down a to matter of $$$- if I'm going to build up 8 it gets pretty expensive pretty quickly. I'm thinking it might be best just to build a rack of 4 now and see how it works out.
The JLM BAN 4 at $595 + a little bit extra seems reasonable- I guess I need to have a think about whether 60dB will be enough for the ribbons- 2 in particular need heaps of gain.

I'd speak to Joe, he is very helpful and might be able to recommends some mods to help with gain required.

EZ1290. Google it and thank me later

Chris H wrote:First time I have heard that it was based on the Amek 9098. Are you sure that is not a net roumour to get the green a bit of legitimacy?
I too have read it was based on an SSL design.

Chris,

I was around the RO DIY forum before (Prodigy)/Group DIY ever existed and for what it's worth and kinda from memory, was approx., the 21st person to be a registered member after RecOrg shut down the DIY forum. To my knowledge, "the Green Pre" as presented by PeterC has always been accepted as described, (again from memory, Amek Mozart) and over the years, no one has ever had the temerity/gaul to question the legitimacy of the design.

Already have 4x EZ1290! I just need more pres! And yes, they are the business.

Something based on a That Corp 1510 preamp chip would be nice and clean, and very straight forward to build. 60dB of gain... just slug a 1646 on end for a balanced output. There are even DC servo circuits floating around the net that will allow you to remove the DC coupling caps...

Ausrock wrote:

Chris H wrote:First time I have heard that it was based on the Amek 9098. Are you sure that is not a net roumour to get the green a bit of legitimacy?
I too have read it was based on an SSL design.

Chris,

I was around the RO DIY forum before (Prodigy)/Group DIY ever existed and for what it's worth and kinda from memory, was approx., the 21st person to be a registered member after RecOrg shut down the DIY forum. To my knowledge, "the Green Pre" as presented by PeterC has always been accepted as described, (again from memory, Amek Mozart) and over the years, no one has ever had the temerity/gaul to question the legitimacy of the design.

Well there you go......i'm obviously wrong
temerity....... i had to look that one up
Definition of TEMERITY
1
: unreasonable or foolhardy contempt of danger or opposition : rashness, recklessness

Would a Yamaha MLA8 fit the bill? I have a couple of these and I find them very clean, but I've never tried them with ribbons. I've found them to be a good solution for 8 cheap pres in 1RU. Supposedly modeled on DM2000 pres with 64dB of gain.

Alistair - the Forssell stuff is as clean as a pre can get - Fred Forssell also designed the AEA ribbon pre which is amazingly clean and good sounding.
SSL - boring

yeah, the Forsell preamps skirt the edge of the theoretical limit for noise. The extra bang in the AEA preamp is the high(er) input impedance that allows many ribbon mics to output an extended top end.
However, the solid state SSL 4000 and 9000 series preamps are also only a couple of 2dB off the theoretical limit for noise but do have a more "normal" 3K or so input impedance.
The Harrison 32 series has a similar design to the SSL and is also very quiet, especially if fully stuffed with the ultra low noise transistor pairs and then tweaked for this setup.
It could be brash to say ... but you'll tend to find the lowest noise preamps are also a tad vanilla.

Thanks guys, a lot of options have popped up now!
The greens look to be the cheapest of the lot, maybe I should try for the best of both worlds and build some Green Pre's and add a high impedance switch as well.
Any idea what the input impedance on the AEA is Rob? Around 18k or something?

I'd love to buy some Forssell pre's, but they are pretty far out of my price range at the moment. I'll have a closer look at this design too to see if I can squeeze anything out of it.

http://www.forsselltech.com/media/attachments/JE16_Mike_Preamp.PDF