All things LA2a related

[kruz]

I'm finishing to compile my shopping list for the bloo, and i'm searching around for a pot like the ones used by UA for R4, R3 and R37 (1Mohm LIN) with that short shaft, slotted to be adjusted with a screwdriver.
I can't find any..
UA seems to use PEC K/RV4 ones, but the shaft seems to be a special order.
Orginial LA2's seemto use AB ones..
I've already browsed a lot of surplus places with no luck.
Do you pals have any source for these?
I know i can cut a longer shaft and do the slot by myself, but it will not stand the professional bloo quality

 

[keithcamilleri]

hi there,

regarding the 510pf newar the 6aq5a does that cap has to be of a type like mica or something i cannot find any thing on the cap....

regards

keith

 

[Scenaria]

kruz...

I have a number for that pot... I'll get it for ya just as soon as I can find it.

keith...

your thinking way too precise...

anything from 400pf to 600pf range will work just fine... mica is will be ok. I think a ceramic would be ok too..

 

[dissonantstring]

hi kruz,
i got this PEC 1 Meg LIN pot from digikey for my bloo kit.
i believe this is the one you are looking for:
the digikey item number is RV4L105C-ND.
here is the catalog page with some specs.
[/url]http://rocky.digikey.com/scripts/ProductInfo.dll?Site=US&V=98&M=RV4LAYSA105A it has a short shaft that only sti...panel when installed. hope this helps. -grant

 

[Siegfried Meier]

Just about to begin wiring up the main turret board. I've got a roll of insulated Buss Bar wire that should work fine, but it's all the same color (white). Any idea what guage and for what voltage I should be buying wire? Thanks!

Siegfried

 

[Scenaria]

24 gauge is fine

believe me its nothing special

 

[SiliconAudioLabs]

OK,

Last question:

So both XLR's shielded grounds (XLR input AND output) go to terminal 7 GND?

 

[dissonantstring]

hi.
i need help!
my voltages check out within tolerance as CJ suggested (within 20%) with the tubes in so i put in the T4 and my Bloo is passing audio, plenty of gain, peak reduction makes the volume go down with no significant compression that i can tell by just listening.
on top of that my meter doesn't even move (stays down to the left). just for kicks i adjusted the zero adjust (eventhough my meter doesn't do anything) and noticed that my NE2 does dim and brighten with the zero adjust pot. i checked the T4 with the cover off and the EL panel doesn't light to input signal. now that i think about it, doesn't peak reduction have to be up in order for the EL panel to start lighting up?
anyway, i've checked and double checked my rotary switch wiring and all seems correct (i hope).
so to sum up:
1) meter does not move in any of the meter settings (GR, +10, +4)
2) no audible compression.
3) T4 EL panels not lighting up (but need to check with the PR up) i guess
that's why there's no compression.
can someone point me into a direction to remedy my bloos!
i know i have to do some tests on the T4 as Keith and Analog Packrat suggested previously on this thread, but i was wondering if there is anything else i should possibly look at?
or maybe i'll just use my Bloo as a nice "audio tube warmer-upper" thingy.
:? any help would be greatly appreciated.
-grant

 

[Scenaria]

well it sounds like you might have more than one problem... if in fact your EL is not lighting at all..

the first thing I would do

pull the T4b module.. this is only needed for compression but the unit will pass audio and add gain without it.

send +4dbu into the input of your XLR jack with a 1Khz osc

switch your rotary switch to +4 position

make sure your peak reduction is tured fully counter clockwise

bring your Gain knob up and look at the meter

does the VU meter move at all?

do you hear the level getting louder as you bring the gain up?

if you hear the level getting louder but the meter does not reflect this then you have something amiss in your meter and rotary switch wiring

if the meter does show the gain as you bring up the gain pot then we can move on...

 

[dissonantstring]

thank you steve!
i'm at work, so i'll have to check when i get off (but that's not til 1am).
-grant

 

[SiliconAudioLabs]

Question about this thread. I'm sorry if I seemed to hijack with my previous question.

Should I post any general question about LA2 HERE in this thread or in the general area in The Lab?

Thanks in advance and sorry (if I got in the way).

:wink:

 

[Scenaria]

yes!

this thread is for all questions related to la2a's

I know its a long thread but I think it makes it easier when searching just one thread instead of the entire forum


I was thinking of maybe setting up two threads..

one for la2a troubleshooting and the other for basic technical questions..

 

[SiliconAudioLabs]

Yeah I think two might work best:

1) General day to day operational, conection (gnd loops/hum/buzz), meter funk, "mines gray maybe I want a silver one..." blah...blah....

2) Then a more detailed techical one like this thread which has already blown up my head three times. :!:

 

[Siegfried Meier]

[quote author="cannikin"]steve;

I'm hooking up the Allied Power Trannie and just want to confirm my connections:

Primary:

1 Black to Live on power connector (Wire to B24 then to B25)
1 Black to Neutral

Secondary:

Center Tap 6.3v (green w/yellow stripe) to ground Bus/TAG 3
Center Tap 250v (red w/yellow stripe) to ground bus/TAG 3

2 - 6.3v (green) to A24 & A25 with heater Wire.
2 - 250v (red) to A22 & A23

Ground:

Grey to Gound on the Power Connector.

Thanks.
David[/quote]

The 2 center tap connections - what do you mean by ground bus/TAG 3? What is TAG 3?

Thanks,
Siegfried

 

[Scenaria]

the tag strips are the two strips that you screw onto the back of the chassis and attatch the power supply caps.

tag 3 would be the 3rd solder lug on that tag strip

 

[Siegfried Meier]

Of course, hence "ground bus".

Thanks.
Sig

 

[Siegfried Meier]

1 more question. Does it matter which black goes to which? Which green goes to which? Or which red goes to which? One color has writing, the other doesn't, which is why I ask. Probably not, correct?

Thanks,
Sig

 

[Scenaria]

it doesnt matter...

if you look on the side of the box that the tranny came in you would see a color code

red and red are your HV taps
Green and Green are your heater taps
Black and Black should be tied to the 120V IEC power socket
the two with yellow stripes need to be tied to ground along with the gray wire.

-s

 

[Siegfried Meier]

Thanks. The help is much appreciated.

And, once again, another question.

SW3 - does it matter what I make Pa and Pb, as long as it conforms to the diagram as far as direction goes? In other words, does it matter how the switch is oriented into the front panel?

Thanks,
Sig

 

[Scenaria]

nope

just arrange the knob accordingly