Vintage Synth Repair

Hello,

I am trying to identify 
the two ICs on the ARP
4072 submodule.  The
schematic shows no ICs
nor does the parts list.

TIA,

Ethan

Looks like standard CMOS logic gates. Get them from Maplin.

Regards
David Wiseman

Electronic Music Services (UK)
44+ 208 478 8242
www.music-service.co.uk

--- In vintagesynthrepair@y..., david@m... wrote:
> Looks like standard CMOS logic gates. Get them from Maplin.
> 

How do you see that 
in the schematic? I am 
using the 4072 schematic
from Arptech.

Thanks,

Ethan

--- In vintagesynthrepair@y..., "ethanzer0" <ethanzer0@y...> wrote:
> Hello,
> 
> I am trying to identify 
> the two ICs on the ARP
> 4072 submodule.  The
> schematic shows no ICs
> nor does the parts list.
> 
> TIA,
> 
> Ethan

Ethan, both IC's are linear types. One is the LM3900N (national 
semiconductor) and the other is a LM1458 (also national part) you can 
also use a RC4558 instead of the 1458. The LM3900 is drawn as 4 
seperate amps in the schematic because there are four OP Omps in the 
one 14 pin IC package.  You should be able to get these from Digikey 
on line. (digikey.com?)

Regards,
John

--- In vintagesynthrepair@y..., "ethanzer0" <ethanzer0@y...> wrote:
> Hello,
> 
> I am trying to identify 
> the two ICs on the ARP
> 4072 submodule.  The
> schematic shows no ICs
> nor does the parts list.
> 
> TIA,
> 
> Ethan

Ethan, both IC's are linear types. One is the LM3900N (national 
semiconductor) and the other is a LM1458 (also national part) you can 
also use a RC4558 instead of the 1458. The LM3900 is drawn as 4 
seperate amps in the schematic because there are four OP Omps in the 
one 14 pin IC package.  You should be able to get these from Digikey 
on line. (digikey.com?)

Regards,
John

Ethan
In case you haven't found your IC's. I have some additional info for
you, plus I have the IC's.

The LM3900 subs to the following numbers, Baldwin, #0514-062023;
Gulbransen, 801823; Lowrey, 991-024542; Wurlitzxer, 142621, 662112;
ECG-992.

The LM1458 subs to the following: Baldwin, 514-126338, 514-063293;
Gulbransen, 801873, 04110; Kimball, 551-009-00; Lowrey, 991-025244-000;
Wurlitzer, 142648, 154278; ECG-778A.

Let me know if you still either or both of them.

Keith Niver
certified MITA technician

mtcasino@... wrote:

> Digikey dose not have the RC-4558 op amp. Newark electrinics dose but
> there is a $ 20.00 minimum.They are about $ .79 each. The Norton op
> amp should be $ .49 or less. mike
>
>      ----- Original Message -----
>      From: jjhannon2001
>      To: vintagesynthrepair@yahoogroups.com
>      Sent: Monday, July 01, 2002 4:10 PM
>      Subject: [vintagesynthrepair] Re: Help Identifiy IC's
>       --- In vintagesynthrepair@y..., "ethanzer0"
>      <ethanzer0@y...> wrote:
>      > Hello,
>      >
>      > I am trying to identify
>      > the two ICs on the ARP
>      > 4072 submodule.  The
>      > schematic shows no ICs
>      > nor does the parts list.
>      >
>      > TIA,
>      >
>      > Ethan
>
>      Ethan, both IC's are linear types. One is the LM3900N
>      (national
>      semiconductor) and the other is a LM1458 (also national
>      part) you can
>      also use a RC4558 instead of the 1458. The LM3900 is drawn
>      as 4
>      seperate amps in the schematic because there are four OP
>      Omps in the
>      one 14 pin IC package.  You should be able to get these from
>      Digikey
>      on line. (digikey.com?)
>
>      Regards,
>      John
>
>
>
>
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> Let me know if you still either or both of them.
> 

I appreciate the info!  I fixed
Arp2600 VCF a while back, but value
your info as I will have more resources
in the future.

Thanks again!

Ethan

Ethan,

Here's the link to the 4072 schematic:

http://www.netcontrol.fi/~jocke/arptech/pdf/4072.pdf

A lot of the submodule schematics are also there!!!

Good luck!

Matt

> > Hello,
> > 
> > I am trying to identify 
> > the two ICs on the ARP
> > 4072 submodule.  The
> > schematic shows no ICs
> > nor does the parts list.
> > 
> > TIA,
> > 
> > Ethan
> 
> Ethan, both IC's are linear types. One is the LM3900N (national 
> semiconductor) and the other is a LM1458 (also national part) you 
can 
> also use a RC4558 instead of the 1458. The LM3900 is drawn as 4 
> seperate amps in the schematic because there are four OP Omps in 
the 
> one 14 pin IC package.  You should be able to get these from 
Digikey 

> on line. (digikey.com?)
> 
> Regards,
> John

Almost forgot to mention...  NTE manufactures a lot of the SCRs that 
are no longer available.  They are available at mouser.com.  You can 
cross-ref the components at nteinc.com.

Cheers,

Guv


--- In vintagesynthrepair@y..., "kanaguvnor" <guvnor@r...> wrote:

> Ethan,
> 
> Here's the link to the 4072 schematic:
> 
> http://www.netcontrol.fi/~jocke/arptech/pdf/4072.pdf
> 
> A lot of the submodule schematics are also there!!!
> 
> Good luck!
> 
> Matt
> 
> > > Hello,
> > > 
> > > I am trying to identify 
> > > the two ICs on the ARP
> > > 4072 submodule.  The
> > > schematic shows no ICs
> > > nor does the parts list.
> > > 
> > > TIA,
> > > 
> > > Ethan
> > 
> > Ethan, both IC's are linear types. One is the LM3900N (national 
> > semiconductor) and the other is a LM1458 (also national part) you 
> can 
> > also use a RC4558 instead of the 1458. The LM3900 is drawn as 4 
> > seperate amps in the schematic because there are four OP Omps in 
> the 
> > one 14 pin IC package.  You should be able to get these from 
> Digikey 
> > on line. (digikey.com?)
> > 
> > Regards,
> > John

hey i am wondering if anyone can give me some advice..

i have lost cv on my arp axxe (ie. every key plays the
same note)
problem is the same from the cv/gate inputs..

it used to work just dandy.. though from the looks of
its insides it has seen some abuse..

it is the black and orange stlye..

any suggestions would be much apprieciated!

thanks!

devin

=====
"nature is harmonius in all of her workings.. and that which is above is as that which is below.."

 http://www.lucidmultimedia.com/uplink

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