racking up an 1108 pre

[kruz]

I'm getting a pair of these puppies and i'm pretty exited to fire them up.
While waiting for the shipping to arrive i was checking this thread...
Hey Soundguy, the links to the docs to your site are not working :sad:
May I ask you if you could send me those docs?
Also, while here, i'm looking around for some daven attenuator as suggested here but i'm pretty confused about what specs i should look for..
Could someone enlighten me? :thumb:

 

[SonsOfThunder]

COOL!! Show us pics!

Any way you can measure the input trafo for the ratio?

Peace!
Charlie

 

[kruz]

Hey Charlie, they are on theri way to my home,
I'll take some shoots as soon as they are here..
about the trafo measurements, ok.. but i'll need help on how to do that..
Anyway i'll let you know when they are here
:green:

 

[kruz]

while i'm waiting for the shipping and a sign from soundguy (check you pm too, please) i'm digging the web to find as much as i can about the 1108 amps..
here is something i've found that could be usefull to anyone:
UA 1967 Products brochure, with specs sheets and photoes, really nice:
http://www.uaudio.com/_works/pdf/UA-catalog-1967.pdf
and a Wayback Machine rescue from old soundguy's site :green:
1108 and AM16 info page
unfortunately, as you can see, the first 3 links about the 1108 are not archived :sad:

well, enjoy :wink:

 

[SonsOfThunder]

Kruz,

If Dave can't email you those files, send me a PM and I'll find the copies that I saved a while back.

Peace!
Charlie

 

[kruz]

Thank you very much Charlie for the offer.
I have found another file that was on soundguy's website (a guy from the old forum had that and kindly sent it to me, thank you Frank)
I've uploaded it on my server:
http://www.beatbazar.com/personal/diy/1108/1108strap.jpg
Seems that now i miss just
1108schem.jpg
1108specs.jpg
If you have them please send me them to kruz at beatbazar dot com
Thank you again, this is the GDIY spirit :thumb:

 

[kruz]

The hunt pays back :green:
Some other GDIY member sent me 10 scanned pages about the 1108 that contains EVERYTHING, even better scans of the few pages found on soundguy's old webpage.
I've grouped all of them and made a nice pdf
here is it:
http://www.beatbazar.com/personal/diy/1108/ua1108-manual+schem.pdf
WARNING 1.8Mb
enjoy

 

[SonsOfThunder]

:thumb: :thumb: :thumb:
Charlie

 

[kruz]

Ok,
You tought i was skilled..
well.. i'm not :shock:
I'm trying to figure out my doubts about the input impedances..
Basically, i want to end up with a mic in, a line in and possibly a instrument in too..
The 1108 manual i posted says that there are 3 stripping choices of input SOURCE impedances, and it also says that the INPUT inpedance is nominally al least 5 times the rated SOURCE. but they do not exactly show us the real input impedance.
anyway.. here are the options:

SOURCE Z = INPUT Z (at least)
600 ohm  = 3000 omh
150 ohm  = 750 ohm
37.5 ohm = 187.5 ohm

I think i can dump the 37.5 one (btw, what was the purpose of this at that time??)
So i can wire the other pair to a switch and have a knob on the front to choose between the two, cool..
So, 750 for mic and 3000 for line.. i tought...
Now, i checked around for similar actual products that have these kind of arrangements, saw that UA 610 and i've been puzzled seeing that the avaiable Z's on the front panel are way higher then what i can have here.

mic  : 500  or 2K
line : 13K
instr: 4.7K or 2.2M

So i was thinking that maybe i could permanently wire my 1108 as 3k and do both mic and line ins..
Am i correct?
Please help, i'm in need to cath up to all these Z issues.. sorry :roll:

 

[kruz]

anyone?

Please, please.. pleeeease

I can offer a beer.. here it is..
:guinness:

:green:

 

[kruz]

THEY ARE HERE.. sexy

NOTE: consecutive pair baby :wink:

BTW, the input trafo (the square grey one) is labelled 5000
While we already know that the output one is the 5002

I'd still have a lot of doubts about my impedances question.. please

 

[andre tchmil]

Hi ,  in an attempt to rack up a Urei 1108 , I'm looking for as much info as possible about connection, pad; volume control etc.
I have the original schematic but could use some extra help/
I"ve seen the glideonfade.com links but all are dead.
Anyone please ?

thanks

 

[mjrippe]

Just uploaded the full 1108 manual to the document section.

 

[andre tchmil]

Just uploaded the full 1108 manual to the document section.

Thank you very much , that was fast  !!

 

[hildy]

Hey All,

Looking to goose a little more gain out of this circuit. I see that Sons of Thunder posted about messing around with R10/R11.  That part of the circuit is adjusting neg feedback, no? What about substituting a different value for R20 or R17?