G9 ????

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Soeren_DK

Well-known member
Joined
Jun 7, 2004
Messages
526
Location
Denmark
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?
 
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.
 
[quote author="Soeren_DK"]Are this the right one?[/quote]
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
 
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: ?
 
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
 
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.
 
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 author="gyraf"]Søren,
are messed up on a regular basis when buying from RS.
.[/quote]
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
 
[quote author="kdawg"]
Sounds wonderful as a DI box too for bass, etc.
-kdawg[/quote]

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
 
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
 
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:
 
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:
 
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.
 
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
 
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