EZ 1290 stereo build 1U

[Spencerleehorton]

Hi guys,

I have just started to build the pcb from madriaanse, very nice boards.
Looking for a cheaper alternative to the grayhill pots, have found this

http://www.ebay.com.au/itm/250949846200

Wondered whether it would be ok, if not anyone suggest some replacements?

Am I right in thinking it is a 2P 12 step pot?

Then there is wiring it up!

Regards

Spence.

 

[iprovlek]

Hi Spencerleehorton!

I think that you must use Grayhill cause PCB is design for this switch!

I have same problem ,I wanna use Lorlin switch but pining is special constructed for this Grayhill switch....

 

[simonsez]

I think you need 3P 12step

 

[Spencerleehorton]

Is there a cheap group buy we could do on oh some grayhill switches?

Regards

Spence.

 

[madriaanse]

I'll add my two cents here by recommending to not take any shortcuts on the rotary switch if your goal is to build a high quality, durable preamp. 

M.

 

[Spencerleehorton]

Grayhill switch pot it is then I think, anyone have a couple for sale?
Or know cheapest please to get them?

Regards

Spence.

 

[useme2305]

spence, you can get them from AML along with the transformers in a bundle. http://www.audiomaintenance.com/acatalog/info_326.html
they also sell them separately.

 

[Spencerleehorton]

Hi Guys,

just wondered if there was a cheaper option rather than £197.16 for 2 grayhill switches and 4 transformers.
be good if i could knock a bit more off.

regards

Spence.

 

[s2udio]

just wondered if there was a cheaper option rather than £197.16 for 2 grayhill switches and 4 transformers.

Well you could go cheaper..........but then it "would,nt be "what it is " ?
Would it.
There are options .......ie use lorlin switches or the type you linked to,(have used them myself),
Wired to the PCB.
Its up to your level of engineering ingenuity and skill level.
I thing , There is nothing in existance as a "cheap" excellent quality audio transformer !
Audio Maintenance and other vendors have a very good range ,at very good prices.
Don,t skimp ....
If a jobs worth doing......then do it well.
Just my 2peneth

 

[Spencerleehorton]

hi guys,

could you help explain or diagram how to wire in an alternative switch please, either lorlin or the other type please.

regards

spence.

 

[Spencerleehorton]

Hi,

What's everyone's thoughts of using polystyrene caps, as I'm led to believe that they sound better?

Regards

Spence.

 

[benqbasic]

hi guys,

could you help explain or diagram how to wire in an alternative switch please, either lorlin or the other type please.

regards

spence.

I believe JLM audio uses the switches with 2 poles.
They have designed a circuit that uses a two pole switch. Im sure they have schematics on their old site.

 

[Spencerleehorton]

Hi,

Only trouble with JLM site is that I will charge me £50 for shipping!.
Not sure if I can use that switch will search for other alternatives.

Regards

Spence.

 

[mitsos]

leftovers from when the wall came down:

http://www.ebay.com/itm/10x-Rotary-Switch-handle-NIB-3-pole-11positions-11p3t-/260974212543?pt=LH_DefaultDomain_0&hash=item3cc34675bf

I bought a two pole version of these. I think the guy mixed up his P's and T's.  I'm pretty sure they should say 3P11T (11T = 11 throw or 12 positions).

Anyway, I haven't installed them yet but they seem durable, except for the knob, one of which arrived broken (4mm shaft is a bit hard to find knobs for...). They have a really excellent heavy-duty click when turning. 

To use them you'd have to run wires from the switch to the PCB, not the cleanest, but it's how Neve's were originally wired..

 

[Spencerleehorton]

hi mitsos,

thats perfect thanks, i was always gonna be running the wires from the pcb even with the grayhill so this saves me a great deal thanks.
any chance you know of a source for the transformers which is also like this!!!
just need to build my psu and source the input/output transformers and i can finish this up.

regards

Spence.

 

[Spencerleehorton]

H guys,

Gonna finish up the psu as per the attachment, carnhill output transformers and marinair input transformer all in 1U case. Just need to alter the heatsinks so everything fits in.
Gonna wire up the switches to the pcb then wire everything and install in case.
Have used polystyrene caps and BC184c transistors.
Looks forward to testing this.

Regards

Spence.

 

[Spencerleehorton]

Hi guys,

Have hit a few snags with this build, output trim pot value? How to wire up and what alterations to make?
Also the output transformer in my 1U case might need a bit of modifying as it is a bit proud!
Just waiting for the last few bits to arrive so I can place it all and start cutting the case.
Psu wise I'm gonna go with the one that's attached below.

Regards

Spence.

 

[useme2305]

spence, there is an almost 100 pages long thread where all of this has been discussed numerous times.
it also contains all of the documentation for this build in the first post. take a look!

 

[Spencerleehorton]

Hi useme2305,

i have read through the 37 pages of the build and the pdf and no mention of how to exactly wire or what value the pot should be or what else to change in what i have read, i have also done a search for 1290 trim pot, trim output etc and have found nothing?
if you are able to help i would very much welcome it, as i am only asking out of failing to have any other option.
Am i looking at the correct thread? only 37 pages, where as you state it has 100 pages?

regards

Spence.

 

[useme2305]

here's the thread:
http://groupdiy.com/index.php?topic=22828.0

basically everything is explained in the first post.

pot is explained here (taken directly from the first post of the thread):
http://s3.amazonaws.com/EZ1290/trimmer_v2.3.pdf