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

[Livingroom]

Regarding my last post, I just found a short on my 340's. Fixed it and now things seem a lot better :grin:

 

[tommypiper]

[quote author="loopermc5"]Tommypiper
I talk to David at cinemag and I went with his suggestion of cmmi-2c for input cmoq-2l for interstage and cmob-2l for output this thing ways a ton and I love it[/quote]

Thanks. Can you tell us how they were wired, please?

It seems to me there is a problem here. The CMOB-2 will only work 1:1, so I don't see how it can work in the circuit, because neither the interstage nor the outputs are 1:1. Can you check on that, please?

 

[Igor]

Hi, got back from vacations, will have some time to help on this week....
questions???...is there people who allready have working 33609's?

@Livingroom:
so, your 33609 working?
r44 0.25W is OK.

@inputoutput:
did you fixed bc184's issue?

 

[tommypiper]

[quote author="Igor"]Regarding trunny's, psb fits TF10016, 31267, OEP A262A2E, LL1540, LL1532 as input, TF10015, 10468, LL1528, OEP A262A2E as interstage. [/quote]

I'm confused. Can we clear this up?

Is T1 Input? Isn't it normally 10468 1:2? (It says interstage above)

Is T2 Interstage? Isn't it normally 31267 2:1? (It says input above)

:?

 

[tommypiper]

And on to T3...

:grin:

What are you guys using?

Anyone using Cinemags? (The CMOB-2 mentioned may not work according to drawings what I've seen... The CMOQ-2 should work. Anyone using any Cinemags?)

Anyone using Sowters?

Others?

Carnhills are expensive from this side of the pond at the moment...

Which ones?

What's the happening, guys?

:guinness:

 

[SWNYC]

Hi Tommypiper,
I've yet to start the build due to not yet receiving the pcb's. I just got the case and Purusha did an outstanding job. Can't wait to get started. Here's what I can gather: T2 is Input. (~2:1 10k:2k4 -6dB) Origanally a Neve L31267 / Belclere TF10016 or Marinair or St. Ives equivelant. T1 is Interstage. (1:2 1k2:4k8 +6dB) Neve 10468 / Belclere TF10015. Take a look at Tekay’s Transformer Cross Table. T3, output (70:600 ~1:2.5 +8dB) a LO1173. I am leaning towards using Cinemag as an output but will wait to get the boards. Hopefully this isn’t redundant and helps out a little. Looking forward to hear what others are using as well.

 

[tommypiper]

[quote author="SWNYC"]
T2 is Input. (~2:1 10k:2k4 -6dB) Origanally a Neve L31267
T1 is Interstage. (1:2 1k2:4k8 +6dB) Neve 10468 [/quote]

OK...

I thought I'd seen it otherwise and different and all mixed up...

odd that they number T2 as the input... but I see that much...

I've seen the schematic, but it doesn't identify the transformer model (i.e. 10468 or 31267).

What Cinemag are you considering for output? Because I don't think the CMOB-2 will work.

 

[inputoutput]

[quote author="Igor"]
inputoutput:
did you fixed bc184's issue?[/quote]

Thanks for asking Igor, yes I changed them, but I’m sorry to say that there’s still no audio going through my PCBs. same on both pcbs. I have a feeling that the error is on the 340 boards, but I haven’t been able to spot it yet. All the Voltages on mainPCB, from your voltages-schems are spot on correct. And I have been changing most of the transistors, just to be sure.I've also randomly checked most of the resistors. so voltage-vise, things seems quite ok.

When I turn it on, the meters go to the top, and then after a minute it turns to zero. So there’s definitively a strong power-signal going to the meters in the beginning there.

Does anybody have a suggestion for me to try next? Should I try an alternative to the 340’ties?

Igor, I noticed that resistors R6 and R60 differs from the original neve schem. (R6=24K and R60=62K). But I guess you have a reason for this?


BTW: I am surprised that a popular DIY project like this has virtually no technical or troubleshooting discussions going. Where is everybody?

 

[Igor]

Hi!
>>>>
Thanks for asking Igor, yes I changed them, but I’m sorry to say that there’s still no audio going through my PCBs. same on both pcbs. I have a feeling that the error is on the 340 boards, but I haven’t been able to spot it yet.
>>>>

Just check out what happens on secondary of input trafo, then on
tp_a, tp_b, tp_c.
If on tp_c you get approx. 25 db lower sin wave than on input,
then check twice ba340.

>>>>
All the Voltages on mainPCB, from your voltages-schems are spot on correct. And I have been changing most of the transistors, just to be sure.I've also randomly checked most of the resistors. so voltage-vise, things seems quite ok.
>>>>

Feels better

>>>>
When I turn it on, the meters go to the top, and then after a minute it turns to zero. So there’s definitively a strong power-signal going to the meters in the beginning there.
>>>>

This is OK, let the unit 10-15 sec to stabilize after power-on.

>>>>
Does anybody have a suggestion for me to try next? Should I try an alternative to the 340’ties?
>>>>

Just see what happens before ba340 on tp_c

>>>>
Igor, I noticed that resistors R6 and R60 differs from the original neve schem. (R6=24K and R60=62K). But I guess you have a reason for this?
>>>>

r6 is actually jumper... r6. same 24k as in orig. schemo; same with r60.

Values printed on pcb are all right.
Except:
There's one resistor on each front pcb (on comp. recovery switch)
which is 24k in one variant of orig. Neve schem and 6k8 in other...
I used older version, then...
it marked r10', located near com. recovery switch and should be 24k.
6k8 will work but recovery will be very fast on 100ms setting.

>>>>
BTW: I am surprised that a popular DIY project like this has virtually no technical or troubleshooting discussions going. Where is everybody?
>>>>

I trying to help as possible...see 2254/33609 tread as well.
You can pm me and I'll try to help you using Skype in my free minute.

 

[tommypiper]

[quote author="Igor"]
BTW: I am surprised that a popular DIY project like this has virtually no technical or troubleshooting discussions going. Where is everybody?
[/quote]

Many of us are still trying to get transformers in the US.

Igor, I have a question. Cinemag recommended the CMOQ-2L to loopermc5 for the line in, T2. http://cinemag.biz/output/CMOQ-2.pdf That transformer is an output transformer. It can be wired 2:1. What do you think to use a big core output transformer for the input?

And for T1, is a humbucking design important to have? Cinemag recommended the CMMI-2C. http://cinemag.biz/mic_input/CMMI-2C.pdf

 

[maxwall]

Tpiper,

glad to see you checking up on these tx's , thanks.

 

[loopermc5]

I would just like to send out a thanks to Tommypiper for correcting my trans former issues with the 33609 I put in the cinemag cmob-2 and it's wrong rookie mistake

 

[tommypiper]

Thanks, Loopermc5, no problem. Wasn't really your mistake, but Cinemag's for giving you the wrong outputs. Yours should sound even better with the right outputs and wiring. Just shows, it's a pretty robust circuit -- works no matter what! :grin:

OK, I've asked around and it seems that the CMOQ-2 should work as a line input, wired 2:1 (T2). It's a bit unorthadox to use an output transformer as an input, but not unheard of...

I would also use a CMOQ-2 as the output (T3), wired 1:2. The "S" version (steel core) probably sounds the closest to Neve originals and should be good.

For T1, the Cinemage CMMI-2C is shielded, it should be OK. (It's working in Loopermc5's...) The 10468 equivalent from Carnhill probably has more Neve tone and also has the humbucking. A Lundahl would work very well there too. (LL1538 and probably others.)

Time to order iron!

:guinness:

 

[maxwall]

Here is a simpler conversion to Cinemag part numbers

33609 Neve to Cinemag conversion ( not exact but close enough if carnhills are too expensive )

Original Tx _______________________Order Cinemag part #
T1 10486 ( mic or interstage tx)................. CMMI-2C
T2 31267 ( Line input tx)............................ CMOQ-2(L-nickel?,S- Steel?) wired 2:1
T3 LO1173 ( Ouptut tx )..............................CMOQ-2S wired 1:2

L-nickel , brighter sound
S-steel , colored sound


question : has anyone else tried the above Cinemag compliment with good success , or is this just speculative results ?

Looking at the dc resistance between the CMMI-2C and 10468(1k2:4k8) , as well as the CMOQ-2S and the LO1173(70:600), they seem quite dissimilar. Especially when using half of the Cinemag quadfilar winding to get a 1:2 ratio and so on.

What compensation method is used to match the dc resistance , if any ?


[quote author="Tekay"]T2 is a step-down transformer 10k:2k4 / ~2:1, TF10016, L31267 or similar
T1 is a step-up transformer 1k2:4k8 / 1:2, TF10015 or L10468 or similar

T3 is step-up transformer 70:600 / ~1:2.5 (+8dB) TF12009, L1173 or similar.

If you use an outputtransformer with an other ratio your limiterthreshold will not track as the limiter section is made to be feeded from a low impedance sorce 8dB below the outputlevel.[/quote]

 

[Livingroom]

Just finished the box and compared to my original(new reissue) 33609 JD it sounds absolutely great. Used Lundahls in/interstage and Marinair for the output. Lots of nice bass, even a little fuller than the belclere gives you in the original.
Thanks so much Igor for a great project, now I'll just have to build another one :grin:

 

[tommypiper]

Great. Which Lundahls did you use? Which Marinairs for the output?

 

[maxheadroom]

i have a small question about the PSU: what does TrimPot R3 exactly do?

 

[JdJ]

[quote author="maxheadroom"]i have a small question about the PSU: what does TrimPot R3 exactly do?[/quote]

You can use either R3 trimmer or R5 fixed (3k57). Igor said earlier that the 3k57 should give you exactly 24v. I used the trimmer just in case I needed to tweak the output DC.

-J

 

[Livingroom]

The trafos I used are Lundahl LL1540 input, LL 1528 inter and Carnhill VTB9056 output.
I said Marinair earlier but I must have had my mind somewhere else sorry :grin:

 

[Tungstengruvsten]

did the lundahls drop right on the board? or mounted off board like the 31267/10468's would be....i've got those trannies but I kinda want to save them for a preamp project since I couldn't afford to buy them again! And the thought of the board mount transformers is appealing, and I have the 9056 output here already...