Soeren_DK

G9 ????
« on: June 10, 2004, 10:34:24 AM »
Hi,

I was inspired of the topic "{NOT!} Sorry my nonexsisting english" and thought that i could ask some questions about the GYRAF G9 preamp...

Can i use 1n4007 insted of the 1n4001?

And can i use Lundahl input trans and OEP trans for the Out?
Quote from: idylldon
...it works like a champ and is as quiet as a mouse pissing on a cotton ball.

http://www.soundcloud.com/doctorsclub


gyraf

G9 ????
« Reply #1 on: June 10, 2004, 10:42:57 AM »
Hej Søren,

Yes, you can use 1N4007's - they are just a higher-voltage version of the 1N4001's

And yes, you can mix and match transformers as you like. The pcb accepts both Lundahl and OEP transformers for both in- and output.

Be sure to get the right OEP transformers though.

Jakob E.
..note to self: don't let Harman run your company..

Soeren_DK

G9 ????
« Reply #2 on: June 10, 2004, 12:46:21 PM »
Thanks Jakob...

Are this the right one?

"This was a long link... It is deleted"
Quote from: idylldon
...it works like a champ and is as quiet as a mouse pissing on a cotton ball.

http://www.soundcloud.com/doctorsclub

mcs

G9 ????
« Reply #3 on: June 10, 2004, 04:04:47 PM »
Quote from: "Soeren_DK"
Are this the right one?

Who knows - the link timed out.

Always write RS part numbers - don't post links. The links only work for 15 minutes or so.

Best regards,

Mikkel C. Simonsen

BackHand

G9 ????
« Reply #4 on: June 10, 2004, 05:30:32 PM »
Has anyone used and/or built a Gyraf Audio G9 preamp?
I'm thinking of building a really good preamp, I would really like to build a Neve but I can't find any easy instructions? Anyone?
How does the G9 sound  :grin:  :wink: ?

kdawg

G9 ????
« Reply #5 on: June 10, 2004, 05:43:09 PM »
I just finished my G9 last week, must say I'm VERY impressed. I'm using OEP transformers. I used the PCBs from Labs (thank you!), I'm soooo glad I didn't try to make my own PCBs. No silkscreening would really suck for this, but more for the Calrec and 1176s that I'm almost done with.

I'd describe its sound as very intimate and warm. It definitely smooths things out and seems to me to have some nice natural compression due to the tubes. Wonderful noise floor, I can really crank it up without any problems. You can really get a nice variety by adjusting how much IN vs OUT ratio. Great to have 2 low pass freqs. Sounds wonderful as a DI box too for bass, etc. I think this will be a staple in recording for me.

Just be aware that this is not going to sound like a solid state preamp. Depending on what your recording you might want something more Neve-ish...

-kdawg

Soeren_DK

G9 ????
« Reply #6 on: June 11, 2004, 12:37:58 AM »
@ Mikkel

hehe... Sorry... Those dam cookies

This is the RS number....

210-6419
Quote from: idylldon
...it works like a champ and is as quiet as a mouse pissing on a cotton ball.

http://www.soundcloud.com/doctorsclub

gyraf

G9 ????
« Reply #7 on: June 11, 2004, 04:52:25 AM »
Søren,

The OEP output transformer should be the A262-A2E as described.
My warning is just because they all look the same, and will fit the
pcb  - and are messed up on a regular basis when buying from RS.

Jakob E.
..note to self: don't let Harman run your company..

Soeren_DK

G9 ????
« Reply #8 on: June 11, 2004, 12:52:41 PM »
Okay Jakob... Thanks... I will check when it is her... I hope i can get it soon.. I can't wait to finished it...
Quote from: idylldon
...it works like a champ and is as quiet as a mouse pissing on a cotton ball.

http://www.soundcloud.com/doctorsclub

G9 ????
« Reply #9 on: June 11, 2004, 12:59:07 PM »
Quote from: "gyraf"
Søren,
are messed up on a regular basis when buying from RS.
.

Oops...
RS is one of my clients!
Their warehouse is just down the road and a team of my collegues have been working there for the past 3 years (i was working there for a while too..)
In fact I had better ask if they do discount


G9 ????
« Reply #10 on: June 11, 2004, 01:55:48 PM »
Quote from: "kdawg"

Sounds wonderful as a DI box too for bass, etc.
-kdawg


Yeah exactly the same observation i made. I kinda regret buying this Trace elliot bass preamp with the intention to direct record my bass since only some time after i finished my G9 and find myself to always use the G9 into the G1176 into the converters of my soundcard. Sounds so much better than the trace elliot.  :thumb:

Flo

XaiuM

G9 ????
« Reply #11 on: June 12, 2004, 12:21:43 AM »
http://www.groupdiy.com/index.php?topic=2757&highlight=#2757

There's a post I made about sound quality of the G9.  I'm in the same spot you are and deciding which mic pre to build.  From the numerous comments I say it will sound great!  Let you know once I start/finish it.

clintrubber

G9 ????
« Reply #12 on: June 12, 2004, 09:13:32 AM »
Quote
Sounds wonderful as a DI box too for bass, etc.


I'm curious if anyone has tried to go twice 'thru iron' for this application...
I mean: putting a Hi-Z buffer (like a neutral DI) in front of the G9 and use the mic-input of thew G9.
This way you pass both the input & output TX of the G9 with possible added niceness. I don't know how much that input-TX does contribute to the fun though.

BTW, this Jensen-circuit would be perfect for this:
http://www.jensentransformers.com/as/as004.pdf

(but use it with your regular 6m cable - so using it near the G9, not directly at the bass-side of the cable to prevent changes in sound due to the disappeared HF-loss from that 6m cable)


Thanks,

   Peter

sismofyt

G9 ????
« Reply #13 on: June 12, 2004, 09:18:03 AM »
I think that is what Dan Kennedy does. Didn't he let us clone his DI input at _the other place_? Or is my memory going bad?

I've done this trick too and I think the instrument GREATLY benefits from that! "The sound is in the iron"  :green:

If Great Rivers design isn't available anymore, then it wouldn't be hard to cook up a FET follower to drive the low Z input. Just be _sure_ not to turn phantom on  :evil:

sismofyt

G9 ????
« Reply #14 on: June 12, 2004, 09:20:00 AM »
Hey Søren, could you edit out that dead RS link? Makes the thread so loooooong  :wink:

sismofyt

G9 ????
« Reply #15 on: June 12, 2004, 09:24:04 AM »
Also, on many preamps the DI is a nonswitched 1/4" jack between the output of the mictrannie and the input of the micamp. This is NOT a good idea!  :evil:  The signal levels are quite low and delicate. The jack is gonna get dirty for sure. I've 'fixed' quite a few preamps with this fault..  :roll:

clintrubber

G9 ????
« Reply #16 on: June 12, 2004, 09:24:44 AM »
Quote
I think that is what Dan Kennedy does.


Right, the very same idea.

So you've done the single or double iron experiment already ? Cool.
And this additional circuit is easy to add.

   Peter

SSLtech

G9 ????
« Reply #17 on: June 12, 2004, 09:26:13 AM »
Soooooo -wide!!!! :?

keith
"A waist is a terrible thing to mind"
Quote from: PRR
Ah, but that was 1999; we don't party like that any more.

sismofyt

G9 ????
« Reply #18 on: June 12, 2004, 09:29:31 AM »
I just made a FET follower with it's own PSU. Unbalanced output that can drive a mic input. Works as long as the center tap isn't grounded!

I could ad a small output trannie to make it balanced but I didn't feel it was needed.

clintrubber

G9 ????
« Reply #19 on: June 12, 2004, 09:29:56 AM »
Quote
Also, on many preamps the DI is a nonswitched 1/4" jack between the output of the mictrannie and the input of the micamp. This is NOT a good idea!



Uhh, so the sec of the input-TX is in // ?

Could imagine to get away with this if there's no prim load for the TX, but it does seem ranzig (Dutch for something nasty).


   Peter