1073 1084 with EQ DIY project HELP THREAD

[MartyMart]

Great pics - which I had not seen before, thanks Pierre.
Got to love those "military" lookin' mustard caps !!

 

[Benny]

Hi.

Do I have to use any kind of special switches for frequency switching (Lo and Presence) or can I just use the usual types in my 1073? I read something about 'cumulatively shorting switches' in an older 1081 thread somewhere. Is it the same with the 1073?

Regards

Benjamin

 

[kazper]

Just regular switches in 1073/84, except the concentric with a through hole pot. That reminds me to check on the 1081 switch lead I had, thanks!

 

[Benny]

Great to hear that.

 

[audioforge]

should be good if you say in your post if you build a 1073 or a 1084
as there re some differences.....


WARNING
I DID A MINOR MISTAKE ON B205 PCBS.THE 2 RESISTORS LABELLED 6K2 SHOULD BE 6K8. SORRY.

audioforge...

 

[MartyMart]

Is there any source for the dual concentric pot/switch for the freq/gain on
these ?
Would be great to have that in one control or are these proprietry Neve pots
and not available.
The 10k pot/8 way switcher etc as used on the BA205.

MM

EDIT - OK, I see that it's being worked on by kazper in this thread :
http://www.groupdiy.com/index.php?topic=25181&postdays=0&postorder=asc&highlight=1073&start=0

Cheers kasper, hope that works out.

 

[MartyMart]

[quote author="audioforge"]


WARNING
I DID A MINOR MISTAKE ON B205 PCBS.THE 2 RESISTORS LABELLED 6K2 SHOULD BE 6K8. SORRY.

audioforge...[/quote]

Pierre, you should be publicly flogged for getting the printed surface wrong
on just two components !! :wink: :wink: :green:
Great job on these, so relax !
MM.

 

[MartyMart]

Are there any other choices of "Iron" for the 1073 ?
I don't have any specs or details for the original, and I know that colin is
selling the "right" ones, but that's going to run to almost $500 for two sets and
I can't quite make that !
( I'm beginning to understand why originals are £2000 a piece ! )

Suggestions or a pointer to the specs so I can have a look around would be
much appreciated.
All my boards are stuffed and ready for their inductors, I'm fitting the sets
from Max with tiny "stripboard" adaptors - should be quite "neat"
Marty.

 

[gec]

-1084
-treble switch assy EK20106

in this schema there are the 4M7 resistors wich are not in the main schema
should we use those?

thanks, gec

 

[gec]

1084

Trying to make a part list, I can't find these components on the scheme:
R1,R3,R29,R39,R76; C12
Does anybody know if they exists?
Gec.

 

[MartyMart]

[quote author="gec"]1084

Trying to make a part list, I can't find these components on the scheme:
R1,R3,R29,R39,R76; C12
Does anybody know if they exists?
Gec.[/quote]

Gec, which board ??
R1/R3 etc are on BA283 / BA284 / BA 211 !!
Marty.

 

[gec]

Marty:

Gec, which board ??
R1/R3 etc are on BA283 / BA284 / BA 211 !!

I referred to the components that are not in the cards, I mean in the manual pdf at page 36 there is the main scheme for the 1084,
the cards are showed with their external pins (not the internal components )
there is a lot of components (till R83 and C19 )
something goes for switches (assembled around switches),
but (PLEASE CORRECT ME IF I'M WRONG) a lot of others are floating...should we connect them point 2 point?
And can we omit the components that I can't find (maybe parts of older releases)?

Gec.

 

[MartyMart]

Gec, look at the drawing EH/10,036 of the complete 1084.

99% of those "floating" parts ( 4m7's etc ) are attached to the pots and rotary
switches.
That whole front "dotted box" is the sensitivity switch with all those resistors attached !

Just one or two will be floating, OR on a small "transformer holding" piece of perf, possibly
such as the 470uf 25v C2 and C? below it.

Relax, it will all come clear we could use the special pots, so a group buy is being
organized by Kasper.

Marty.

 

[gec]

1084
what is RV1 in the Ba283 card for? Is it a normal trimmer or should we take care of something (case, power rathing,...)?

I didn't see any switch from Kasper yet, and I would like to make it as soon as possible in a 2 units chassie (with no room problems ), so these are my question about switches and pots?

Is the BA194 switch a 3 poles 6 position? where can I find one?

I'm going to put a volume knob, removing the 5K1 resistor between pin E and K, should it be linear or log?

Gain knobs on the eq: should those be linear or log? should those be center detect?

I don't understand the Hi Q switch drawing, what kind of switch is that? what happens to the 7k5 resistor when it's on and when it's off?

Thank you

 

[bergis]

Have I get it all wrong but in the schematic for the B205 there is only 2* 6,2K??? not 6,8k like you said was wrong...

 

[Rob Flinn]

[quote author="gec"]1084
what is RV1 in the Ba283 card for? Is it a normal trimmer or should we take care of something (case, power rathing,...)?
Thank you[/quote]

That trims the class A output stage of the BA283 for Asymetrical clipping. i.e so it doesn't clip on the positive half of the cycle before the negative & vice versa. You do not need a special trimmer in this position

 

[kazper]

I'm working toward a group buy for switches, I've spent more effort for the 1081 project because it uses some odd type switches.

I have a interest in the 1073/1084, since I too have a set of PCB's.

I'll try to look into both of them during the week and try to post something when I have enough good info.

Kevin

 

[ProfPep]

Interesting tip about frequency response from a former Neve employee.

http://www.auroraaudio.net/aa_html/tech_tips_01.htm

 

[Tekay]

There are several versions off the BA205, older ones used 1k2 and 9k1 instead of 620R and 6k2. There was also a version with 620R / 6k8 :? Changing the serialresistors to the low cut/boost potentiometer will also change the frequency slighty, but we're talking hertz not 10's off them.

 

[audioforge]

Gec
b194 switche: 3 decks 1 pole 12 or 6 positions .or a 2 decks 2 poles 6 positions.
eg here http://www.banzaieffects.com/Rotary-Switches-c-275.html

others swithes classic lorlin 2 poles 6 positions and one 1 pole 12 positions.
about the switche that show 4m7 resistors on the individual schem.and not on the main 1084 schem. the 4m7 R. are here to "avoid" pops between switche positions..it doesn t hurt if you put them.

about the 6k2 6k8 on the b205.... one schem show 6k2 the ams ones 6k8.
on 205 pics i have no red line on thoses resistors so i guess ther s 6k8...
rev. changes???
volume pot log
eq pot i guess linear (no center detent on the original)
audioforge
ps thomas nice to see you here :wink: your neve knowledge and help is more than welcome......