Official 33609 builder's tread. See 1st page for updates.

[wassx]

sry the mess.
It was just a foolish measurement from TP_A to the ground of the case.
Thx Igor for your time!

I made now the measurements and compared it to the 33609_SCHEM_VOLT.jpg
in brackets the right voltage


Board I:
TP_A 3,9 V (4V)
TP_B 3,9V
TR4 17,0V (17,4)
TR3 17,0V (17,4)
R55/56 17,6V (18V)
TR2 3,5V (4,1), 0,65V (0,64), 4,1V (4,7)
TP_E 0,6V (0)
R52 0,6V (0,6)
TR6 7,2V (7,0), 20,5 V (20,4)
R22 1,6V (2,5V) <----???
TR7 24V (23,7), 0V (0V)

This board has -23dB switched Bypass OUT and 0dB Bypass IN. Limiter and compressor board have no effect.

Board II:

TP_A 2,9V (4V) <---???
TR3 19,2V (17,4), 18,6V (17)<---???
TP_B 3,1V (4)<---???
TR4 18,6V (17)<---???
TP_D 11,5V (11,6)
TR2 0,647V (0,64), 3,4V (4,1V), 4,0V (4,7)
TR9 0,6V (0,6)
R2 23,8V (24), 23,3V (23,6)
TR6 7,2V (7), 20,5V (20,4)
R15 17,4V (17,4)
TR10 6,6V (6,4), 17,4V (17,4)
TP_F 0V
R22 1,6V (2,5) <---???
TR7 24V (23,7)
D9 0V
TR12 0,6V (0,6)
R62 0,1V (0)

The board behaves like Board I, but instead of 0dB it has -3dB output.

Any ideas based on these values please?

I have no scope at the moment, so I must stick to my meter.

 

[Igor]

Hi, it will be hard to figure out what happens without scope...
Please check the CV voltage, without gain reduction it should be 0V
at anodes of D14, D15. Then, after triming RV-1 correct, audio should be unity gain with makeup switched off.
If CV is 0v and you have -23dB when bypass off,
then, something incorrect in audio. Apply 0dB to input, then go to
tp_a, b,c,d, and check signal.
r22: check out polarity of 2.7 v zener.
Just get one board working, second will be easy.

 

[Underthebigtree]

I discovered a near perfect mounting bracket for the Carnhill VTB9056 output transformers at Home Depot.

Buy a package of Ook 1/8" steel offset mirror holders, part #50220, for two bucks. You will get 4 steel brackets with a hole in one end. Drill a hole in the other end, and use a vise to bend the brackets 90 degrees in the middle. Attach 2 brackets to each transformer by unscrewing the nuts holding the transformer together on the side opposite from the soldering pins. Put the pre-drilled hole over the screw, then a small washer, then put the nut back.

Once both brackets are on, you can use your vise to bend them to a clean 90 degree angle. Drill holes in the bottom of the case that match the holes you drilled in the metal brackets (I use a silver Sharpie on the black case for my guide marks - works great on the black metal) and you are done.

Hope this helps someone!

-Nick

 

[promixe]

This is how I did it:

Bought a perforated piece of metal about 7"x3" (at Home Depot in the section where they have vent/heat metal hardware and brackets), drilled a couple of extra holes in it, bended, painted, put damping foam on the sides. Got a few of 2" metric screws (identical to the ones in the transformers, only a little bit longer). Used a single bracket to mount both xformers. VERY firm, looks better in reality than on pics. =) Took me about 20 minutes total for 2 units I'm making (excluding paint drying time).

I wish the boards worked though. =( Still can't pinpoint the problem... Wassx, have you figured out your problem? It seems somewhat similar to mine...

 

[Igor]

promixe, wassx: how it goes?
Are you solved the issue?

 

[promixe]

Okay, here is what I'm doing and where I'm at:

1) I input a 1Khz sine wave that measures 0.774V (0dBu). At Pri+ in reference to T2 GND I get exactly the same reading. At Pri- I measure 0.768V (-0.074dBu).

2) At the T2 Sec+ I measure 0.341V (which is -7.13dBu), so the signal goes down an extra dB from the specified -6dB at this point. At Sec- it is 0.332V (-7.36dBu).

3) At around R11 the signal goes down -31dBu which is correct according to the schematic. At TP_A it is 0.022V (-30.5 to -31dBu). At TP_B it is 0.014V (-35dBu).

4) I’m getting 18.2VDC at both TR3 & TR4 bases. Is this within the acceptable range from 17V? At TR4 Collector it’s 3.353VDC, at TR3
collector it’s 3.325VDC. How far off from 4V can it go? Is this OK?

5) Igor, are you referring to 0VDC at TP_CV? I’m measuring 0.063VDC there (to chassis GND).

6) Then, at T1 Pri+ I still measure -31dBu, but at Sec+ (which I think is TP_C) it goes to -21dBu (instead of -25dBu like on the schematic?). On the scope it looks like a healthy sine wave though, so the signal is going through that stage fine, just the dB figures are off.

7) It is still -24.8dB down at the output with Bypass OFF and everything else out. I’m not moving further until I hear my testing so far is OK. Also, at TP_D I'm getting -1.5dBu (Isn't it supposed to be -8dB there?)

Thanks in advance for any clues =)

 

[Igor]

Hi!

1) I input a 1Khz sine wave that measures 0.774V (0dBu). At Pri+ in reference to T2 GND I get exactly the same reading. At Pri- I measure 0.768V (-0.074dBu).

OK

2) At the T2 Sec+ I measure 0.341V (which is -7.13dBu), so the signal goes down an extra dB from the specified -6dB at this point. At Sec- it is 0.332V (-7.36dBu).

Still OK, it dependant on source impedance and trunny's....

3) At around R11 the signal goes down -31dBu which is correct according to the schematic. At TP_A it is 0.022V (-30.5 to -31dBu). At TP_B it is 0.014V (-35dBu).

TP_A and TP_B should be equal DB but out of phase.
Hook scope's trigger to say input signal or TP_A than see if tp_b in
opposite phase to tp_a.

4) I’m getting 18.2VDC at both TR3 & TR4 bases. Is this within the acceptable range from 17V? At TR4 Collector it’s 3.353VDC, at TR3
collector it’s 3.325VDC. How far off from 4V can it go? Is this OK?

Still OK, in healthy tolerance.

5) Igor, are you referring to 0VDC at TP_CV? I’m measuring 0.063VDC there (to chassis GND).

Still OK.

6) Then, at T1 Pri+ I still measure -31dBu, but at Sec+ (which I think is TP_C) it goes to -21dBu (instead of -25dBu like on the schematic?). On the scope it looks like a healthy sine wave though, so the signal is going through that stage fine, just the dB figures are off.

Check if you wired the trunny correct. Which trunny you used?
How does it connected now?
T1 should be 10468 kinda trunny connected 1:2.

7) It is still -24.8dB down at the output with Bypass OFF and everything else out. I’m not moving further until I hear my testing so far is OK. Also, at TP_D I'm getting -1.5dBu (Isn't it supposed to be -8dB there?)

BTW, did you get 0db in / 0db out with bypass IN?
I.e. signall passing thru relays and in/out connectors well?

Check the interstage trafo (t1) where you get extra gain.
But, this is not the reason to get -24db out....
Are relay jumpers for 12/24v relays installed?
If there's healthy sinus at tp_d, at -8dB or more level,
audio path is healthy.
There's extra 4 db of gain from T1...
just fix it, probably wiring....
some extra spare (approx.2 db) from output circuit-OK
then, you set output with RV1.
So, it is OK you see out is -1.5 db with RV1 at max.

Check errata on first page of this tread about output pins on schemo.
Maybe output trunnie?
Check with scope signal going to output trunny's pri,
and at secondary of output trunny (ground -out of out. trunny
and watch +out with scope).
A way strange...

Something really simple....check all after TP_D.
And tell ASAP what it was, a way curious

 

[Linus]

I'm having trouble tracking down a couple resistors.

400 Ohm, 1/4w, 1% metal film

2.6K Ohm 1/4w, 1% metal film

If these two are not available. What do I substitute?
I have 390 Ohm, 1/4w, 1% metal film. Is that an OK substitute?
I have 2.7K ohm 1/4w, 1% metal film. Is that an OK substitute?

 

[crisotop]

connect some easy to find values in series?

christoph

 

[promixe]

Check errata on first page of this tread about output pins on schemo.
Maybe output trunnie?

I see you're bringing your Remote Sensing Abilities (RSA) to a previously unheard of level. =) How stupid, I'm almost ashamed to even mention what was wrong, but for sake of future generations of DIY builders I'm gonna say: OUTPUT TRUNNY'S PRI- & SEC- WERE SWAPPED! =)

After probing the audio path with the scope and seeing nothing out of the ordinary I've decided to hot-swap the output trunnies for a second and the output level jumped right back to 0dBu! =) So I rearranged the pins in the molex and this one channel seems to work fine now =) Is there anything more stupid that you guys have done or am I just winning the contest hands down? =)

Anyway... Gonna see if the second board is OK and then on to calibration (where I will probably have more questions)..

Igor, THANKS again man! =)

 

[Amnezia]

Wich resistors are the "effect" one's... R23 and R41...?
In the BOM it's just R23 - 300 OHM / R41 - 1K2... ? :?

But on the Main PCB it seems like they are drawed in bigger scale?.. :roll:

Thanks in advance.. :thumb:

 

[Igor]

Hi, even as RSA-called (nope!), can't understand...

Wich resistors are the "effect" one's... R23 and R41...?

PLS x'plain

OUTPUT TRUNNY'S PRI- & SEC- WERE SWAPPED! =)

HURRAY!!!!!!
Told ya, it's simple!!!!!


These kinda mistakes are usual in common practice, all we're
people with human factor etc....The prob is as dumber is mistake,
it takes more time to find it.
Anyway, happy with one board up...waiting for pics of working unit!

 

[promixe]

Ok, here is my first calibration problem:

4.3. APPLY MAX. OUTPUT FROM SOUNDCARD TO INPUT, AT LEAST +10DBU,
LIM IN, ATT FAST, RECOVERY 50, LIM THRESHOLD TO +4, COMP OFF,
ADJUST RV4 TO +4 AT OUTPUT.

Feeding like 12dBu. With RV4 maxed out (most CW position) I'm getting +3.13dBu, not +4dBu... Why would that be?

Also, at 5.2 I'm getting -0.6dB with COMP IN with RV5 at most CCW position... So I can't finish calibrating either COMP or LIM section..

Also, the meter is not dead on precise - if I adjust correctly for 20dB at step 4.2, then 8dB is undershooting a little bit. If I readjust for 8dB dead on, then 20dB is overshooting. Is there a solution to this?

UPD: RV4 & RV5 scenario is the same for BOTH boards. RV5 goes a little closer to 0dB at step 5.2 (It read -0.4dB, not -0.6dB like the other board). The RV4s are both at -3.1dBu...

 

[Igor]

Did you fixed gain issues? Please check all TP values in db
are same as on schemo (+/-0.5dB) first...
I have a strange feel, interstage was connected 1:4, not 1:2...

Trafos: ratio:
input T2 pri/sec -6db
interstage T1 pri/sec +6 dB
output T3 pri/sec: +8 dB

check the load on output trafo sec (I use 1k...1k8)
than, maybe change com and lim threshold trimmers, RV4 and RV5,
to 50k.

Also, the meter is not dead on precise - if I adjust correctly for 20dB at step 4.2, then 8dB is undershooting a little bit. If I readjust for 8dB dead on, then 20dB is overshooting. Is there a solution to this?

Just calibrate them to 0 when no gain reduction with screw...
then, recal for 20dB, should be OK.
Or, maybe, scale placed wrong.
If there's 1...5 degrees it is OK. Just calibrate for 20db reading,
if it shows 7 or 9 instead of 8, just say :"Analog!"
Which meters you used? Are both showing same error?

 

[promixe]

have a strange feel, interstage was connected 1:4, not 1:2...

Trafos: ratio:
input T2 pri/sec -6db
interstage T1 pri/sec +6 dB
output T3 pri/sec: +8 dB

I think you're correct once again =)

Pri/Sec Ratios:
T2: -7.2dB
T1: +11.7dB (so looks like 1:4, but I don't get it how it could be)
T3: +4dB (I guess compensating for incorrect T1 ratio)

My T2 is Carnhill 9046 wired in series.
My T1 is Carnhill 9045 wired in series as well. I wired both traffos according to Rob Flinn's post on page 20 of this thread:

Primary: pin2 to PRI+, pin3 to pin4 (CT), pin5 to PRI-, pin6 to GND
Secondary: pin7 to SEC+, pin8 to pin9 (CT), pin10 to SEC-, pin11 unused

Is this incorrect?

HERE it says you get +6 by connecting pri/sec in series, which I did. But I'm getting +12..... on both boards....

Did you fixed gain issues? Please check all TP values in db
are same as on schemo (+/-0.5dB) first...

1st board:
Input: 0dB
T2 sec: -7.2dB
TP_A & TP_B: -32.7dB
TP_C: -21dB
TP_D: -2.3dB

2nd board:
T2 sec: -7.1dB
TP_A: -31dB
TP_B: -35.5dB (???) - but it's inverted phase on the scope like it should be (see pic below)
TP_C: -21dB
TP_D: -2.3dB

 

[promixe]

UPDATE: Just noticed there is no signal at T1 SEC- (pin10), is this a normal behavior? Both boards have no signal at that point... PRI- is sine, SEC- is nothing.... weird.... Could it be BOTH faulty trafos? That's some $$$... =\

 

[Igor]

Hi!

Pri/Sec Ratios:
T2: -7.2dB

OK

T1: +11.7dB (so looks like 1:4, but I don't get it how it could be)

Wrong. At tp_c should be -25dB (+/-1db).
Just check all across T1 and connection of T1.
Even maybe pull T1 out of circuit just to measure and be sure trafo is 1:2.

T3: +4dB (I guess compensating for incorrect T1 ratio)

T3 should be 1:2.5 (8db) ratio.
This can cause low lim. threshold prob, because limiter detector reference
to signal _before_ transformer.
Which trafo are you using as T3?
If the level at tp_d is -8db, output should be 0 (+/-1db).

My T2 is Carnhill 9046 wired in series.
My T1 is Carnhill 9045 wired in series as well. I wired both traffos according to Rob Flinn's post on page 20 of this thread:

Primary: pin2 to PRI+, pin3 to pin4 (CT), pin5 to PRI-, pin6 to GND
Secondary: pin7 to SEC+, pin8 to pin9 (CT), pin10 to SEC-, pin11 unused

Is this incorrect?

Don't have experience with Carnhill's, used Beclairs and StIves. For StIves, it is correct...they should be equal to Carnhills.

HERE it says you get +6 by connecting pri/sec in series, which I did. But I'm getting +12..... on both boards....

Yes, strange. Please check everything across T1.

1st board:
Input: 0dB
T2 sec: -7.2dB
TP_A & TP_B: -32.7dB
TP_C: -21dB
TP_D: -2.3dB

2nd board:
T2 sec: -7.1dB
TP_A: -31dB
TP_B: -35.5dB (???) - but it's inverted phase on the scope like it should be (see pic below)
TP_C: -21dB
TP_D: -2.3dB

First board seems right except extra 4 db.
Second board, just check everything to get equal level at tp_a and tp_b.

Then, if the signal at tp_d is -2.3db, output is 0db???? Strange.
Put gain makeup at 0, lim and comp off, then adjust output (RV1) for 0db,
at tp_d should be -7...-8 db.
Just 2 strange things: not equal tp_a, tp_b on second board
and trafo ratios. Check everything, it should work
(if there's more than 50 of 33609's done on
these pcb's working 100% right, no reason your is special!!!)

UPDATE: Just noticed there is no signal at T1 SEC- (pin10), is this a normal behavior? Both boards have no signal at that point... PRI- is sine, SEC- is nothing.... weird.... Could it be BOTH faulty trafos? That's some $$$... =\

T1 sec is ground...Just take some time and relax, than continue with comp's. I remember, it took me a while to get first 2254/33609 hybrid
working 100%...just keep going easy.
:guinness: :sam: :guinness: :sam:

 

[promixe]

Which trafo are you using as T3?

Carnhill 9056 - people have reported it's working beautifully in the 33609...

Then, if the signal at tp_d is -2.3db, output is 0db???? Strange.

Very strange, indeed =)

Put gain makeup at 0, lim and comp off, then adjust output (RV1) for 0db,
at tp_d should be -7...-8 db.

RV1 at most CCW position reads -3.8dBu at TP_D and -1.56dBu at T3 secondary. With Output at 0dBu TP_D reads -2.23dBu...


Going to check T1 ratios later tonight...
There is a thought in the back of my mind that I'm not measuring stuff correctly... =) Apply sine that reads 0.775VAC at T2 PRI+ (measured to T2 GND). Then measure voltages with my VAC meter everywhere in reference to T2/T1/T3 GND and convert to dBu with something like this - http://www.sengpielaudio.com/calculator-db-volt.htm. Since I don't have any special tools I have to do it the long way: measure AC voltage, convert to dBu, etc... Bypass IN, everything else OUT (unless trying to calibrate LIM or COMP)... So in other words, when I read out dB ratios, it's always + to GND or - to GND anywhere, not both...

UPDATE: Just took T1 out of the board, measured +5.4dB with pri/sec in series... When feeding -31dBu sine into it standalone I read around -25.5dBu on secondary... So all is good with the traffo... What else would cause it to drop an additional 6dB within itself when in the circuit??

UPDATE: Checked T3 out of the board, measured -8.3dB... When feeding -8.3dBu sine into primary, I get exactly 0dBu from secondary... So all traffos seem to be alright... =\ What else would affect ratios being that much off? Especially T1: I can't get my head around WHAT would make the T1 change its ratio when it's in the circuit =\ Have you guys had xformers changing their ratios by factor of 2 without rewiring them differently (i.e. physically changing parallel/series arrangements)? =) It looks like primary of T1 would have to be in parallel to get ~12dB boost. But that's physically impossible because nothing is connected to pins 3&4.... lost for now... =)

 

[Amnezia]

Wich resistors are the "effect" one's... R23 and R41...?

PLS x'plain

quote]
Maybe i'm just stupid.. but what is "PLS"?... If it's the manual.. the link is down?.. :?
Please help me out.. don't want to ruin or burn anything just because I did something stupid.. :wink:

 

[promixe]

[quote author="Amnezia"]
Maybe i'm just stupid.. but what is "PLS"?... [/quote]

"PLS x'plain" in this case, I think, refers to "Please explain" =)

From your previous post:

Wich resistors are the "effect" one's... R23 and R41...?
In the BOM it's just R23 - 300 OHM / R41 - 1K2... ?

I personally only understood the word "BOM" =) So, all this means, you have to explain what you are trying to ask more clearly, because so far none of us can't understand what you mean, and therefore we are unable to help.

I think somehow you are confused that on the PCB silkscreen the outlines for those two resistors (R23 & R41) look somewhat bigger than the rest of the resistor outlines on the board. If this is your concern - those resistors should be no different in size or wattage, just make sure they are the right values (as it is printed right on the board and in the BOM)...