universal 610 schematic?

[enthalpystudios]

i f'in love it.

got to love this forum man.... just saw your a25 post too cj, and theres a cool sheet of le papier scanned on your site about the specs.

but on your page, cj, there's 8ma of dc listed on the a25's datasheet, the yellow one.

Thats where the 8ma came from.

So does magmetals still carry that lam? ;]

 

[CJ]

Mag Met has that lam in their catalog.
If there is a customer still using it, you can get samples.

But, if you are contemplating doing what I think you might be doing, it would probably be cheaper to buy the darn thing.

5000 t is a lot for a diy'er.

But I just spun 7500 t of #43 on a section of the V-72 choke for jens, and it was not that painful.

The A- 25 uses abot a 42 or 43 for the pri.
#36 sec.

Learned the theory behind the F lam, since there is usually flux fringing around a gap, if you stick the gap inside the coil, the mag field from the turns helps keep the fux from spreading outside the gap, which keeps your leakage down. Thats if you get the windings real close to the lams, which means, no nylon, just layered paper.

 

[enthalpystudios]

expensive lams eh....

and yeah, that's a lot of turns. i hit 100 turns and start getting dyslexic.

i need to do a little hand drill winding setup

that b11178 job i did took it out of me, hand wound

what if an 'approximation' was wound on a bigass EI core? 75ei maybe?

i'm not a huge stickler for exact vintage... besides i have an O1, that gets in the ball park ;]

the knobs have WAY more of an effect on HF response, anyway.

 

[Brian Roth]

[quote author="Winston O'Boogie"][quote author="Brian Roth"]

Well, *anything* is better than nothing, since Universal Audio has a "no schematics" policy!i[/quote]

OK then it's here:

http://www.revolutionrecording.com/images/610A-Schematic.pdf


Basic differences betwixt this and the 6176 are the eq, the output stage and the input transformer. The 6176 also has a MOS/Zener reg for HT (the 2-610 doesn't however) and, if I recall (it's been a few years), the heaters are 12V instead of 6V as used on the old 610 and the newer 2-610.
Good luck fixing it, hopefully nothing major.[/quote]

Thanks for the schematic link. It turns out that my client had swapped a 12AX7 into the second tube position vs. the correct 12AY7/6072! That seriously compromised the MOL before clipping.

The 6176 does indeed have a different output stage. After some PC board tracing, I found that the final section of the 12AY7 has a 47K plate load resistor, and the signal is then capacitively coupled into the output xfmr's primary.

Bri

 

[NewYorkDave]

47K? Wow... seems kinda high.

With the correct tube installed, how much plate current is flowing? Did you measure the ratio on the output tx? I'm just curious. R-C coupled, plate-driven, parallel-fed transformer outputs are not easy and I speak from experience. The only thing that really makes it worth doing is because it's so damn hard to get iron that's suitable for series feed.

 

[Brian Roth]

I measured right at 3 mA through the output stage. The xfmr is a 7:1 ratio (test measured 10 VAC into the primary for 1.43 VAC out).

Bri

 

[madriaanse]

Hi Winston,

Thanks for the info/schematic!!

What is the B+ on that schematic, and also, which Lundahl in/out do you recommend? (part #'s would be niiiiice!) :thumb: I was thinking maybe a LL7903 and LL1630/5mA, but I'm not very good at this stuff?

Many Thanks!!

Martin

 

[NewYorkDave]

Thanx for the info, Brian. It sounds like they're running the output stage a little cold, considering the load it has to drive.

 

[enthalpystudios]

1630/5ma is probably the closest stock lundahl output for this, by my estimate.

you should try looking for a utc O-1, they pop up on ebay all the time. also try searching for a TRW O-1.

 

[gary o]

Interesting stuff... im bit late I think but would love to have a look at the 610 schematic if any1 wouldnt mind sending me a copy.

Thanks guys ...................Gary O.

 

[gary o]

Im not so great at the technical stuff got a Sowter huge output transformer a 9040 seems to me wrong ratio for the 610 seem can take the 3 ma ok ,,,question is would it sound ok ?????

If not good for this any ideas on what I can yous it for ?????

Heres whats at the Sowter site on it...........



ideal for most low power triodes. Reflected load may be adjusted by adjusting the load resistance.
FEATURES A very large core to ensure a high bandwidth and low output impedance. High grade grain oriented silicon iron (M6) core for minimal losses and harmonic distortion. Multi section winding ensures minimal leakage inductance for an exceptional bandwidth. Low copper resistance which permits an output impedance of 87 ohms when driven from a valve with rp = 1000 ohms and a secondary load of 600 ohms.
Ratio Z ohms (nominal) Primary inductance (large signal) I dc DC Resistance pry / secy Bandwidth
(3 dB points)
5:1 15k:600ohms 50 H 40 mA 650 / 34 ohms 20Hz-60kHz
(5000 ohm source)

 

[lotus]

So i've got a couple of utc o-1, Can anyone send me a schematic as well? Forgot to save it the first time around. tks

 

[theremin]

I would appreciate any schematic contributions you all could give

I am trying to create a good resource for audio engineers at RecordingJunkie.com

Most of the content will be for studio techs rather than designers, but any materials are helpful. I will keep adding to the archive as long as I have room on the server. If it won't fit I will archive and make available on request items.

I am doing my own research and legwork trying to find as much as I can, and get permission from manufacturer's wherever I can find a contact. If I can't then I will do a removal on request thing , but hopefully noone will see this as a bad thing.

Signing up for the forums is not required for submissions or viewing, but it is nice to see my own community grow a little

Appreciate any help.

S!
Jason[/url]

 

[gary o]

I no this is old thread I was just looking for schematic for this the original 610 & not the la610 thing....I see its gone....back then I did a ghetto DIY version of this amp & I used the Sowter 5:1 ratio transformer......my question was how will it sound with this part answer is bloody brilliant ! the amp is hiding in a box with 2 other pre amps I was gonna re build it but il think il leave it alone as it works well.

 

[QUEEF BAG]

this is the only thing i have on it,  the amphenol connector is only needed for use in a console.

there is an original 610 here, and it is freakin' amazing.
another case of F* the reissues.

 

[LUIZ PAVÃO]

A caminho....

E não desse "Eu também! Eu também!" material: razz:

CJ bom dia. Você poderia ter a gentileza de me enviar uma cópia dos diagramas do UA610? Muito obrigado antecipadamente. [email protected]

 

[LUIZ PAVÃO]

QUEEF BAG. Obrigado pelo esquema "UA_610_micpre. pdf". Ele é bem diferente do "SOLO610 MIC" que tenho aqui. O meu aqui usa uma tube 12AT7 e uma 12AX7. O transformador de entrada é um ALTRAN C-3799-8.

 

[Schmilsson]

QUEEF BAG. Obrigado pelo esquema "UA_610_micpre. pdf". Ele é bem diferente do "SOLO610 MIC" que tenho aqui. O meu aqui usa uma tube 12AT7 e uma 12AX7. O transformador de entrada é um ALTRAN C-3799-8.

The schematic and thread regards the original 610, not the reissue which you seem to be looking for.

 

[LUIZ PAVÃO]

Obrigado ESQUIMÓ pela atenção.

 

[gyraf]

..please keep posts in english - use google translate if needed..

/Jakob E.