SSL 9K Mic Pre

[Harpo]

[quote author="3nity"]is anyone running the Keith psu on a 30VCT transformer?
that gives a +41 as phantom... i'd like to reach 48V perfectly...[/quote]
No need to change the resistors. With a 15-0-15V transformer your 41V seems the max.voltage you can pull out of this doubler curcuit (2* (15VAC * 1,414 -0.6V diode drop)=41.22V, may vary depending on line voltage). You'll either need a 40VCT transformer (as labled in schematic), using the KPS-1 pcb or a voltage trippler to get your min.51V raw DC before your regulator.

 

[Siegfried Meier]

Got a quick PSU question. I'm using the regular PSU that comes with the 9k pre. My transformer is an Amveco 62074 which is supposed to have an 18V 1.944a output - which the PSU board wants to see. I just measured my transformer, and for some reason I'm getting 22v out. No idea why, but will this be a problem for the input of this PSU board? Or will it just use what it needs?

Thanks!
Sig

 

[Harpo]

[quote author="Siegfried Meier"]Got a quick PSU question. I'm using the regular PSU that comes with the 9k pre. My transformer is an Amveco 62074 which is supposed to have an 18V 1.944a output - which the PSU board wants to see. I just measured my transformer, and for some reason I'm getting 22v out. No idea why, but will this be a problem for the input of this PSU board? Or will it just use what it needs?

Thanks!
Sig[/quote]
Hi Sig,
no problem. From Amveco datasheet http://www.amveco.com/Miniature_Low_Profile_Transformers.htm this 2x 18VAC is 2x 20.9VAC unloaded and your local line voltage may be a little 5% higher than 115/230VAC.
-Harpo

 

[kenrinc]

I'm using an avel lindberg Y236205 22v ct torroid. It's like 50va because I'm power two API 312 and two 9ks but now I'm not sure it's what I need. I get 52v in series and 26.5v in parallel. What does the input of the 9k psu need to see?

ken-

 

[khstudio]

[quote author="kenrinc"]I'm using an avel lindberg Y236205 22v ct torroid. It's like 50va because I'm power two API 312 and two 9ks but now I'm not sure it's what I need. I get 52v in series and 26.5v in parallel. What does the input of the 9k psu need to see?

ken-[/quote]

#1 - That Tranny is too big (too much voltage) for BOTH Preamps.
You should get an 18v-0-18v or 20v-0-20v TX (MAX)

#2 - TX's will read a higher voltage when UNLOADED.

#3 - don't run it "parallel"... Both pre's need the center tap setup.

 

[kenrinc]

Thanks Kevin. It's been so long since I ordered parts I have no idea what I was thinking when that thing showed up! Cheers.

Ken

 

[3nity]

Hey i tried to lower the +/- 18V with the help of some diodes to +/- 15 but with 2 in series only went as far as 17V....

Am i doing something wrong here?

thanks

 

[mushy]

Hey i tried to lower the +/- 18V with the help of some diodes to +/- 15 but with 2 in series only went as far as 17V....

Am i doing something wrong here?

thanks

It takes 5 or 6. I think I used 5.

 

[kenrinc]

R81 and R117 have given me fits with that weird 50k value.  Does it have to be exactly 50k?  I have some really huge 50k resistors but it would be nice to go with a standard 1/4w form factor.

Ken

 

[Siegfried Meier]

Read through this entire thread - I used a pair of 100k in parallel, works amazing.

Sig

 

[kenrinc]

Thanks Sig.  Didn't think about that.  Two 100k in parallel work great. 

I was told I could "load" the transformer with a 3.9k on the output for testing.  That's the secondaries out of the torroid?  So I'm assuming that would be from the CT to either side of the output?

Ken

 

[Slenderchap]

OM-01-073 is now the preferred choice for the pot .... it is a better alternative to OM-01-060.... it has a 10% track, longer life, 1/4inch shaft, long shaft.

Colin
www.audiomaintenance.com

 

[Whoops]

Hi,
having some problems finding the inductors.

can anyone tell me if I could use any of this ones? and if so witch is the best candidate for the SSL9k?

http://pt.farnell.com/epcos/b78108s1153k/inductor-axial-15uh/dp/608506

http://pt.farnell.com/epcos/b82111bc23/inductor-axial-15uh/dp/9752137

http://pt.farnell.com/tyco-electronics/sc30m-15uh/inductor-axial-15uh/dp/1173903


you help is highly appreciated,
thanks

 

[kenrinc]

I see why I bought the 22-0-22 tranny: it's in the friggin BOM for the PSU!  Oh well, guess I'll go with a Avel 18-0-18 as the Antek's seem to be too big to fit in a 1u chassis (at least a par metal one).

Whoops: I'm in the US and found the part number at Mouser.  Digi was obsolete.

$.02

Ken-

 

[noulou]

Hi,
having some problems finding the inductors.

can anyone tell me if I could use any of this ones? and if so witch is the best candidate for the SSL9k?

http://pt.farnell.com/epcos/b78108s1153k/inductor-axial-15uh/dp/608506

http://pt.farnell.com/epcos/b82111bc23/inductor-axial-15uh/dp/9752137

http://pt.farnell.com/tyco-electronics/sc30m-15uh/inductor-axial-15uh/dp/1173903


you help is highly appreciated,
thanks

Use the first one, because it is the cheapest. The second one has lower resistance but that makes no difference in this circuit.

I used them in mine and it works perfect.

 

[Whoops]

Thanks,
nice one.

So basically in this circuit you just need to have a 15uh choke the other specs of the inductor don't matter that much, is that right?

 

[gerardmanvuca]

I think theres an mistake in Neeno parts list,

for the Power supply C6-C11 probably should be 100nf like it says in the schematic and not 100uf as is mentioned in the parts list.

Please someone comment this....

I have just realised I have used the     35V,1000uF (Nichicon) as stated in Keith's BOM and not 100nf for C6 to C11, what consequences could this have on the sound?

- on the channel balancer, what voltage do i need for the four 100uF and the C1 - C2 (capacitor) 100 nF?

thanks,

G

 

[MartyMart]

I have just realised I have used the     35V,1000uF (Nichicon) as stated in Keith's BOM and not 100nf for C6 to C11, what consequences could this have on the sound?

- on the channel balancer, what voltage do i need for the four 100uF and the C1 - C2 (capacitor) 100 nF?

thanks,

G

On the Gustav PSU the 1000uf 35v and other large electro's are obvious and correct.
( look at the footprint and legend on the boards )
The small 5mm pitch poly's are all 100nf caps
On the balancer boards I used 25v for the 100uf's to be safe.
MM

 

[kato]

On the balancer boards I used 25v for the 100uf's to be safe.

The 100uF caps on the balancer board are for protection against accidental connection to a phantom powered line. To be safe those caps should be 63v.   


(or 50v)

 

[MartyMart]

My bad - I meant 50v !!!