905 general questions

[synthguy]

Boy Howdy!

After about an hour or so of poking and prodding, I finally got a picture from my IPad to this forum.
A First!!!

This is the "stuff sheet" I mentioned before.
It includes all of the component locations that i could actually see in the photos, and I've marked the power and ground rails as well.

Hopefully we can get some different angle pics to verify some things. I've pointed out what I think is a jumper that is currently hidden or unclear in the pictures I've been able to find.




Hope this helps!

[Omega56]

Hello everyone,

and now something complete different ... ... no, not really... but ..
When you are not repairing an existing 905 but you want to create a clone, which spring do you use. I had a look at the accutronics springs and there are a lot of springs. All a bit different... 2 main things I am looking for: Which type should I choose? Input insulated, output insulated OR input grounded, output insulated OR Input insulated, Output grouned OR Input grounded, Output grounded?
If I understand the schematics correctly then the last one should be avoided. And the input side is connected to ground (output to -6V). So Input grounded, Output insulated sounds not so bad. What's your opinion?
Next is the input impedance / DC resistance. Again there are a bunch of values available (from 8 Ohm to 1475 Ohm). Is there any general rule for that?

Thanks again in advance for your answers.

Bernhard

[noddyspuncture]

Hi Folks,

I have now extracted my 905 reverb from my cabinet and have had a look at those points for you.

I can confirm that my -6volts is indeed used and does indeed go to the output of the reverb, and also the 75uF/2.2K - 10uF - 100ohm and 82K components as shown in the schematic...!

Also the mystery "un-named resistor"... on my unit it is a small preset trimmer... and needs setting quite accurately for the recovery amplifier to actually work without being too noisey...

Here are some more photos of mine...
Cheers,
Tom

[url=https://flic.kr/p/E6nKMZ][img]http ... .jpg[/img]905_6 by noddyspuncture, on Flickr[/url]

[url=https://flic.kr/p/DDgi2s][img]http ... .jpg[/img]905_7 by noddyspuncture, on Flickr[/url]

[url=https://flic.kr/p/D8DKeN][img]http ... .jpg[/img]905_8 by noddyspuncture, on Flickr[/url]

[url=https://flic.kr/p/D8Z5TD][img]http ... .jpg[/img]905_9 by noddyspuncture, on Flickr[/url]

[url=https://flic.kr/p/DUWVj1][img]http ... .jpg[/img]905_10 by noddyspuncture, on Flickr[/url]

[url=https://flic.kr/p/DDgh33][img]http ... .jpg[/img]905_11 by noddyspuncture, on Flickr[/url]

[url=https://flic.kr/p/DUWUDy][img]http ... .jpg[/img]905_12 by noddyspuncture, on Flickr[/url]

905_13 by noddyspuncture, on Flickr

[url=https://flic.kr/p/DwTza8][img]http ... .jpg[/img]905_14 by noddyspuncture, on Flickr[/url]

[url=https://flic.kr/p/E6nHyF][img]http ... .jpg[/img]905_15 by noddyspuncture, on Flickr[/url]

[url=https://flic.kr/p/DX8B7V][img]http ... .jpg[/img]905_16 by noddyspuncture, on Flickr[/url]

[url=https://flic.kr/p/D8Z3Ea][img]http ... .jpg[/img]905_17 by noddyspuncture, on Flickr[/url]