It's Alive!!! diy81

[tommypiper]

[quote author="fuzzbox"]Okay so I got the output amp working :grin:

She sounds amazing. Compared it to my Ward becks(460's) Langevin Am16, and well it sounds alot more open, detailed, large..[/quote]

Woohoo! :grin: I think you do win the First Prize now.

About the output trafos, are you saying there are different ways of doing it in the different schematics? I believe it's meant to be interfacing with 600 ohms.

The distortion seems like maybe something else is going on though...?

 

[fuzzbox]

Tommypiper, yeah maybe something else but what?
If I just plug it directly into my AD ( a soundscape apogee)
http://www.sydec.be/Products/Details/ID/06eff631-6297-49e0-ac3c-e0f9724fab80/Apogee+I%2fO+896/
It works no distortion sounds beautiful.
It just distorts when plugged into the 1176 or the decca's, thats why I was thinking impedance.
On the user guide it shows a diagram for the output tranny with 470R resistor strapped to pins 1and 3, On TT's it has a 100r resistor strapped to pins 2 and 4, I've tired both same result. I can't locate the third version,
I've got files for this thing everywhere.

 

[fuzzbox]

Okay I'm very pleased with myself!!!
I figured out my problem. I had the wires feeding the output transformer
inverted. Shes working like a charm. I can say it's a done deal.

An interesting note, I was calibrating the output and noticed the line input
was 3db shy of 0db (+4) but at the first step, not good! I believe 0 should be step 5. Looking at both motherboard layouts theres a difference with Tommytones board where you have 2 extra resistors, R20 and R21.
They are running after the connection with the line input transformer then feeding the gainswitch. I bypassed them and am now getting 0db (+4)
at step 5 of the gainswitch, maybe someone more knowledgeable can figure that one out.

Anyone know where I could find those illuminated switches for the Eq bypass/phase/solo/phantom.

Time for a box and a couple of faceplates.

Bluzzi I'm gonna start bugging you, I got a ha-100x, hs-50, T4b on my shelf itching to get used.

 

[Bluzzi]

No problem, bug away! (I've got an octal socket for you if you need it).

I've got 1 LA2A all wired but haven't fully checked my wiring yet (have to finish painting the kids room first). Already found I had my AC mains Hot wired to transformer instead of switch! That could have been scary!

If you haven't started yet you may want to look at the LA2A circuit board. Many have already successfully finished them and are very happy.

The longest thing for me was the metal work. My friend had to leave and start his own company and it took time for him to get all the machines setup and running. If you need any metal work done let me know.

(oh yes, I'll be bugging you too, as I have all my parts for 2 GSSL's along with sidechain filter)

Your 1081 is pure beauty!

jim

 

[ChuckD]

That's Great News FuzzBox!!

OK I was waiting for someone to finish, because I really didn't want to be the first on this one. So I have been sitting and watching for a while now. I am starting my 2 channel 1081 this weekend then!! Can't wait! Super excited that the design works!!!!

Talk to everyone soon.

-ChuckD

 

[tommypiper]

Chuck, did you find pots that fit with the knobs? I'm still looking for pots i can use without modifications.

 

[ChuckD]

I dunno??
To be honest I haven't looked at any parts since getting the switches from the group order.
I did not order the knobs due to lack of funds at the time and figured I wouldn't really care what knobs I was using... I guess we'll see.

I don't have the switch legend. Does anyone have a way to identify them?

-Chuck

 

[just.sounds]

Sowter has some neve inductor models and they offer a pcb version.

9815 Neve T1280 EQ Inductor
9810 Neve T1295 EQ Inductor
9805 Neve T1230 EQ Inductor
9312 Neve T1530 EQ Inductor

Maybe they compare to the one you miss?