SSL 9K & 4K (E Series) 500 / 51X NEW BOARDS Mic Pre Thread 2011

[Graph]

Any ideas why relays arent working?

Thanks!

 

[Graph]

I solder Leds hoping Relays works, but no leds arent lightning up either.

The curious is leds arent working neither.. they get some voltage at one leg measured to ground, and get voltage at both legs in the other position... maybe its a ground related problem? Should i try it on a lunchbox? (since i am not using a lunchbox right now, only a slot of rackit from igor)

Thanks!

 

[mtw]

Thanks!

I think it's indeed the best approach to just compare them... Any tips what to look for first? Starting with tracing the AC signal, looking for DC offsets, etc?

Tzman - did you ever track down where your problem was? I am having the exact same issue.  I've gone over the solder joints for the feedback networks at each IC, re-seated all the ICs, played around with the high pass trimmer pots... nothing has helped.

 

[tzman]

Actually I didn't...
I spend some evenings trying to track down the error and comparing it with my working unit, but no dice...

I eventually ended up buying a new PCB and almost all new components which I'm about to put together. I'll report back here if the new one is working. I'll be using the same pots and transistor.

 

[Graph]

Well.. My SSL9k5 are in the lunchbox they just look great, working i can say.

Sorry my bad.. 150r, were actually 150k... i only hope it is the only resistor value they missed marking, but after 3 hours checking all resistors, i found only those.

Low LVL from mics, fixed: Since 150ohms resist
Relays: Fixed, working fine.
Leds: not working yet, i will check it in another moment.
noise: only at high lvl gain.. now.. i wont use more than 12 o clock, so.. no issue.

 

[mtw]

Actually I didn't...
I spend some evenings trying to track down the error and comparing it with my working unit, but no dice...

I eventually ended up buying a new PCB and almost all new components which I'm about to put together. I'll report back here if the new one is working. I'll be using the same pots and transistor.

Hi tzman (and others who happen to be listening),

I bought a replacement THAT1646, a bunch of NE5534 and a couple of OPA2604 ICs and started methodically swapping parts around. I also went through the HPF calibration routine.

The biggest change was replacing the TL052 with the OPA2604 - I was instantly able to set the gain higher before oscillation started. This is a summary of what's happening now:

Gain Position at Oscillation	HPF	Phase	Pad
12 o'clock	off	off	off
3 o'clock	off	on	off
12 o'clock	on	off	off
3 o'clock	on	on	off
full gain (no oscillation)	on	on	on

I'm still scratching my head about why flipping phase has such a big influence on oscillation. Then again I'm still a dilettante when it comes to electronics!

 

[mrdarwin]

Hi!

Can we build this preamp without LED meter? just ommit it?
to build a multi preamp rack not in 500 format....

thanx

 

[culteousness1]

Sure. I think it's already covered in this thread but you can just leave the meter board out.

Then you can omit the precision rectifier circuit on the main card too. It's the section from
C7 to M1-OUT and M2-OUT in the schematic.

Cheers,
Carsten

 

[mrdarwin]

Thank you very much for this information culteousness1!

 

[mtw]

I took some time to do further debugging on the oscillation issue and I may have found something interesting. (or maybe not??)

When I plug a dynamic mic (Blue Encore 100) into the unit, I can get the gain to about 12 o'clock before oscillation kicks in.

When I connect the unit to my audio interface (MOTU Ultralike MK3) via balanced XLR/TRS, and feed it a sine wave, I can get the gain all the way up without oscillation.

Does this failure mode point to something obvious?

 

[audiosway]

Are there any more 4K boards available? I am looking for 8 more.

 

[culteousness1]

Are there any more 4K boards available? I am looking for 8 more.

Unfortunately not as Gustav decided to discontinue the 4K5.

Maybe you can source some boards in the Black Market.

Cheers,
Carsten

 

[Gustav]

Are there any more 4K boards available? I am looking for 8 more.

For 8, you can mail me. (I won't hav time to do them the coming week, but I could put them in queue).

I discontinued the 4K board because the demand was pretty low - especially compared to the 9K boards.

Gustav

 

[audiosway]

Are there any more 4K boards available? I am looking for 8 more.

For 8, you can mail me. (I won't hav time to do them the coming week, but I could put them in queue).

I discontinued the 4K board because the demand was pretty low - especially compared to the 9K boards.

Thanks. I'm PMing you now. I love the sound of the 4k and am going to build a sidecar out of them.
Gustav

 

[Gustav]

Are there any more 4K boards available? I am looking for 8 more.

For 8, you can mail me. (I won't hav time to do them the coming week, but I could put them in queue).

I discontinued the 4K board because the demand was pretty low - especially compared to the 9K boards.

Thanks. I'm PMing you now. I love the sound of the 4k and am going to build a sidecar out of them.
Gustav

I got stuck with a full panel of 4K5 on this order. I am tired of having space taken up by the stack, so If anyone is interested, Ill sell them as a lot at a good price (use mail).

Gustav

 

[jasonallenh]

Are the 51X only? I've only got a meager 500 Series  :-\

 

[bruno2000]

Are the 51X only? I've only got a meager 500 Series  :-\

They work fine in a 500 rack.  Just cut off the unused fingers.  There's a dashed line to tell you where.
Best,
Bruno2000

 

[gnarmageddon]

Ceremoniously cracking my knuckles to build my first two 9k5's

Has anyone done pushbutton switches instead of toggles for hpf/pad/inv/+48 - and if so, what part did you use?

 

[AyoK]

Hi there!

I'm a newbie in the DIY-field and I just finished my shopping list for the 9K. I'm wondering if it is possible to use this inductor http://www.banzaimusic.com/Panasonic-ELC09D-15uH-20.html or any other inductor from Banzai as a substitute for the 15uH MICC/N-150J-00?
Or should I just stick to the alternatives mentioned in this thread like the 77F150K-TR-RC from Mouser? The thing is that Mouser charge 20 euro for shipping and since I don't need anything else from them, I'm hoping to find an alternative at Banzai where I'm buying everything else from  

Thanks

Ayo

 

[culteousness1]

Hi Ayo,

unfortunately, the inductor from Banzai is a radial leaded inductor which won't fit in this design.
Please update your profile with a location. It will be easier for members to suggest a local alternative
without paying 20 EUR for shipping.

Best,
Carsten

PS: Welcome to GDIY!