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

[late]

Anyone knows is there sound differences between bc441/bc461 and 2N5320/2N5322?

If you have bc441 and bc461 for reasonable price send PM, please.

 

[prescott]

Hello!

I'm building this comp too, and need some help.
I'm buliding it with Lundahl trafos, but one thing is not clear:

T2 (in the middle of the PCB) is the input trafo's place?
So is it the place of my ll1540?

I've read the whole topic, and I see what can I use for input and for interstate, but I dont know which is which on the PCB...
So T1 (on the left) is interstate (ll1528) and T2 is input (ll1540)?

Thanks!

 

[jplebre]

If you are looking at the PCB with the letters facing the correct way, input is in your left labelled as INTR1 L31267 or equivalent 2:1, interstage in the middle INTR2 L10468 , o/p transformer connects to the far right OP_TR molex connector

 

[prescott]

Thanks!

 

[prescott]

What can I use from Lundahl for the output?
Can you guys suggest me something?

 

[jplebre]

I'm not really familiar with Lundhalls, but you want an equivalent to the Carnhill VTB9056 or marinair L1173
Maybe ask your supplier, or someone else might pitch in, but this is an old thread.

Looking back at the replies, most people went with carnhill or cinemag o/p even when using Lundhall's in the other positions

 

[guavatone]

Some audio examples:

Can some one run the unprocessed file through their unit AND/OR the original 33609(C/J/JD)?

Original: http://dev.ax-design.com/electronics/33609/33609-test4a.mp3

Compressor IN (THD -4dBu / 100ms RECOVERY / +6 GAIN / 4:1 RATIO): http://dev.ax-design.com/electronics/33609/33609-test4b.mp3 - the 100ms problem was fixed by replacing R10 with 24k

Limiter IN (THD +4dBu / 100ms RECOVERY / FAST attack): http://dev.ax-design.com/electronics/33609/33609-test4c.mp3 - you can hear the distortion. I don't know what it would be attributed to (see next link)

Limiter IN + Compressor IN (setting are as above): http://dev.ax-design.com/electronics/33609/33609-test4d.mp3 - really distorted signal. Compressor smoothes the track, adds gain makeup, and then the limiter freaks out. It sounds like there is an overload somewhere along the limiter sidechain. Where would I look? It calibrated fine though...

Examples C & D sound pretty horrible if you ask me =)
Example B on the other hand really remind me of the classic neve-ish mixing desk sound. That one gives me hope =)

I would really appreciate if someone replicated same settings on their unit (DIY or original) and posted audio. I can provide space for it on my server if needed. Thanks!

hello promixe,

have you found a solution regarding your problem with the distortion of the limiter?
i have the same problem. especially on limiting the bass as single signal i hear great distortion when i turn the limiter on.
anyone else have this problem?

Is this a fluke or is there a circuit problem?

 

[jplebre]

Nope.
I had 2 Igor 33609C and a J/D side by side and had several audio engineers coming in and blindfolded.
There's a small difference in low frequency "grab" which does feel like the low end breathes a bit more on Igor's C.

For everything else, the unit is damn spot on.
7/10 in the blind test swapping between C and J/D most of the engineers that came in were unable to spot the differences.

I felt I had some drum tracks where the low end thing was noticeable and everyone in the room actually preferred the C.

 

[t-wurst]

Hey fellas, need a little help point me in the right direction. Build Igors 33609 - everything worked fine for long time. One day, one channel stopped working, i noticed one burned resistor (R40 or R44 - one of the first after the PWR connector) - i replaced it but one channel still is dead. VU works when comp is IN, behaves normal but is dead quiet as soon as i switch the Comp IN via main COMP IN (that one besides the link switch) no matter if the channel bypass is in or out. BA340 gets slightly warm but touchable... I have 24 Volts on BA340 connectors. Could it be dead. Could it have caused the burned r44? How can i test it? Some ideas? Thanks a lot!!

 

[prescott]

Would ll1676 work on the output?
I have a pair of them....
What do you think?

 

[Olegarich]

If this one project still alive? is there any place to purchase pcbs?

 

[prescott]

There are no more pcbs I'm afraid...

 

[valco]

Hi ,

I bought some of the last pcbs of the 33609 that Igor had and now I have finally begun to try and order parts and figure it out. But the powersupply seems to be different from the earlier revisions and i can't find any info or BOM on the one i got.

Is there anyone who can help me with the BOM or pinpoint me to where i might find some more info ?

 

[jplebre]

that looks like the Sontec power supply.
Igor in the latest stages was sending whatever power supply he had at hand because he usually designed them all the same.

I do think you might have a problem because you need the extra bit this power supply had for the initial callibration.

I would like someone else to pitch in on this as I'm not sure if the power supply can run unloaded or if there's something else I'm missing, but you could literally just stuff the positive side of the PSU as you only need the ground and the 24v rail. That 24v rail supplies both boards and then you can tap some hookup wires for the bypass/meter/led pcb.

bom for the sontec PSU:

Qty Value Device        Parts           
                       
DIODES             
4        1N4004        D20, D21, D22, D23
4        1N5400        D16, D17, D18, D19

RESISTORS 1/4w pitch 10mm MF 1%
1  10k  R-EU_0207/10  R24             
2  200  R-EU_0207/10  R4, R5 
1  rx+  R-EU_0207/10  R1    3k6 for24v         
1  rx-  R-EU_0207/10  R7    3k6 for24v 

IC'S
1  317  LM317        IC1             
1  337  LM337        IC3

CERAMIC CAPS 0.1UX50V PITCH 2.5MM
4  0.1  50v  C2.5/2      C9, C10, C11, C12

ELECTROLYTHIC  CAPS 50V
4  100u  50v CPOL-EUE3.5-8  pitch 3.5mm diam 8mm
2  3300u 40-63v CPOL-EUE7.5-18             
            PITCH 7.5 OR 10MM 

2  HEATSINK FARNELL 1313891 , 1315516 , ETC

The rx+ are what adjusts the voltage to the LM. Make sure you put 3.6k (again, I'm not sure if the value changes if you are only running one side.
Be careful with the orientation of the molexes cause this caught me of guard on another project.

Hope it helps?

You will still need to source a 3v supply for initial procedures. You can just do a little proto board or even breadboard where you tap of the regulated 24DC and stick a TL071 like this

 

[prescott]

Can someone help me troubleshooting my boards?

I have the same problem, that other members had, but I do not find the solution for the problem.

If I feed 0,775v on the input I can get only 0,445 on the output. It looks like it stays in gain reduction. I have a big attenuation on the output...

I've read Igor's notes on floating but It's not totally clear for me.

Thanks!

 

[jplebre]

Probably going to state the obvious, but did you check if your signal goes through the right attenuations through the circuit? you can see on schematic that there are notes of what the signal gain should be at each point of the audio circuitry.
That should give us an idea where the problem is.

Did you double check your wiring for the trafos? Did you put the small boards under the trafos to avoid shorting?
Which DOA are you using? are the voltages correct for the DOA? are the all the parts specific to one or another DOA installed (or removed, whichever is the case?)

If you have the feeling that you have constant GR, did you check your molex connector wiring? One reversed Diode or e-lytic cap could cause what you are describing.

Hope it helps. This is a big project without more info (unless someone that had the exact same issue can pitch in) is a bit hard to help.

 

[prescott]

I have ll1540, ll1528, and ll1676 on the output (ll1676 will be changed)
I have app992 DOA with the additional components. I had to change a resistor and now I have enough gain. 1.3k to 360r.

The problem was: I sorted some of the transistors while measuring the voltages. So I changed all of them for new ones. I used bc550/560 for experiment, but seems working perfect.
I have less than -110db noise, I think its very good, its because the 992 DOA i think...

Now I'm at the point of calibration. I have 0 dbu in, 0 dbu out. Calibrate the CV, its OK.
After it, its inpossible to calibrate the meter. I turn the trimmer on the PSU to have -20db on the output, I correct the meter to show 20db. Than back to -8db on output, and the meter is 12 db. Adjust to show 8, that 20db out again, and I have 16db on meter.
This 4db difference I always have....

It looks like its OK until 4-8-12db, the problem comes when going higher especially between  16 and 20db reading.

I went through the calibration with DBU and DBV, same result.
I cannot move further with the calibration until I dont know what is the problem...

 

[salomonander]

anyone know where i can find a schematic/technical handbook for the original metal knob version?

 

[salomonander]

anyone know where i can find a schematic/technical handbook for the original metal knob version?

nevermind i found the original handbook. the schematics are pretty different in some areas to j/d, j or c version. MUCH more tantalums in the original. different cap values as well.... some styroflex etc. no suprise that the original sounds different....

 

[ruairioflaherty]

anyone know where i can find a schematic/technical handbook for the original metal knob version?

nevermind i found the original handbook. the schematics are pretty different in some areas to j/d, j or c version. MUCH more tantalums in the original. different cap values as well.... some styroflex etc. no suprise that the original sounds different....

Can you post that schematic?  Handbook?