Carl_Huff

Nice internal shots of A.P.I 550b
« on: December 19, 2004, 02:08:37 PM »
Anybody know what brand of rotary switches those are??

They don't look like anything that I recognize.
Best Regards,
Carl Huff


Ethan

Nice internal shots of A.P.I 550b
« Reply #1 on: December 19, 2004, 02:09:53 PM »
They look distinctly like grayhill
I am just the Web Geek here.

tubejay

Nice internal shots of A.P.I 550b
« Reply #2 on: December 19, 2004, 03:38:10 PM »
Boy, would that, or something similar be a nice DIY project...  Anybody know of any DIY project design that could be done using discrete opamps like this?  Maybe a melcor EQ?

nrgrecording

Nice internal shots of A.P.I 550b
« Reply #3 on: December 19, 2004, 03:59:10 PM »
By the way...
whats with the 525 or AM2B comps... some time ago in this forum.. soundguy?  :roll: any news?  :green:
Frank Röllen. www.energyrecording.de [FORUM · DIY WEBSITE · STUDIO]°°°° www.frontpanels.de [Engraved Frontpanels]°°°°

soundguy

Nice internal shots of A.P.I 550b
« Reply #4 on: December 19, 2004, 04:23:02 PM »
Buttachunk has my am2b schems right now, I tihnk it would make a fine DIY by looking at it however its a spring time thing at best for me, I leave for the road in a few days and dont know which end is up right now.  I still havent been able to get my hands on a 525 so, there was a cool one on ebay a few weeks ago, my priorities are elsewhere right now.  Those definitely look and feel like greyhill switches, however Im sure they are custom.  It would be an easy thing to build if someone wanted to design a board, they really arent too expensive though, Id rather just buy one, the resale investment is practically %100, building one will be costly and you'll have trouble getting your investment out of your DIY if you ever sell it in comparison.

dave

chips are good with dip...

Bryson

Nice internal shots of A.P.I 550b
« Reply #5 on: December 19, 2004, 04:50:08 PM »
I see no inductors or gyrators....Or is that what those three-transistor sections are?

Bryson

Nice internal shots of A.P.I 550b
« Reply #6 on: December 19, 2004, 04:51:55 PM »
Quote from: "Viitalahde"
Quote from: "tubejay"


http://www.danalexanderaudio.com/ApiInfo/550AschemT.jpg

550A schematic.




Take the "T" (thumb) out of the link.

tubejay

Nice internal shots of A.P.I 550b
« Reply #7 on: December 19, 2004, 04:59:56 PM »
I guess I haven't used an IC opamp based eq that I thought sounded as good as an API eq or other discrete neve type eq's.  If there were a way to make a two or four channel discrete eq for a reasonable amount of money, that would be pretty cool. Maybe a design similar to the 550a using OEP's or Cinimags and Melcor amps.  I don't know.  Soundguy is probably right on making a replica api, it would probably be better just to buy some.  If the switches were separated and made using common parts, it might be worth while and cheaper to do.  I'm not smart enough to figure it out myself though.    :evil:

TomWaterman

Nice internal shots of A.P.I 550b
« Reply #8 on: December 19, 2004, 05:27:33 PM »
Cool piccies!

Those switches are definitely Grayhill! They are pretty good to deal with as a company. If this ever became a DIY thing - they can make these switches to order. EAO is their european distributor.

Lead time is about 7 weeks and I'm guessing the price would be between £50-100 for the dual concentric switches. A prime candidate for a group order.....

I'm getting some 12way, 4 deck 71-series from them, £26 each as an indicator of price (but a 24 position 4deck is £82).

By the time you add up four of those concentric switches - it would get a little pricy. I would love to make a pair of something similar - not the same but wasn't TK going to donate his 'EQ73' to The LAB?

Dave could well be right, @ around £600 a module they are affordable.....still gotta have a rack to put 'em in. Thats £500 more.

Would be nice to eventually make an API-esque dicrete EQ.

Cheers for the link Jaakko!

Tom



soundguy

Nice internal shots of A.P.I 550b
« Reply #10 on: December 19, 2004, 06:57:24 PM »
the opamps in this EQ make a tremendous difference.  I have a 550 that blew a 2520 and it now has a AD in place and it sucks in comparison to my other 550's.  Im not saying that if you dont use a 2520 that you are doomed, but which ever opamp you choose, you are definitely gonna hear it, so chose one that you like the sound of as it will be an integral part of the sound the EQ makes.

dave

chips are good with dip...

SSLtech

Nice internal shots of A.P.I 550b
« Reply #11 on: December 19, 2004, 07:05:34 PM »
If the op-amp is going to be asked to tame an output transformer directly (as they often do in API gear), it will need a large pair of cajones in terms of output current drive.

The 2520 and the Melcor have big brass balls in the output pair area, things like the TL071 have "mincy little f*ggott balls" to quote Vinnie Jones as 'Bullet-Tooth Tony' in "Snatch". An AD or even a (reasonable capable) 5534 will need to be followed by a beefy NPN/PNP pair.

Keith
"A waist is a terrible thing to mind"
Quote from: PRR
Ah, but that was 1999; we don't party like that any more.

soundguy

Nice internal shots of A.P.I 550b
« Reply #12 on: December 19, 2004, 07:22:27 PM »
that most definitely explains what is going on...  I didnt put it in there, yet another thing to fix...

dave

chips are good with dip...

rlaury

Nice internal shots of A.P.I 550b
« Reply #13 on: December 19, 2004, 09:36:11 PM »
I just did a rough cost to build on the 550B in low quantity (25 pcs).
It comes to about $750.00 not counting tooling, PCB development ect.
the switches kick yo butt at about $85.00 - $95.00 ea. You would have to use a differnt OpAmp. API doesn't sell them any more unless you trade in a bad one.

Just once, I'd like to build a custom console. API style. just for me.
maybe 32 channels. Dynamics, PC based moving fader. No holds barred! It would take around $3000.00 per channel. Anybody want to place an order?? 50% down. delivery in 120 days.

RonL

http//:www.nashaudio.com
When all you have to work with is a hammer,
everything looks like a nail.

tubejay

Nice internal shots of A.P.I 550b
« Reply #14 on: December 19, 2004, 09:43:44 PM »
That's what I'm talking about.  Get rid of the original switches, use melcors, and then use readily available pots and switches (non dual concentric) and it'd cost about $400 less.  $350 per channel is more like it, and that would be worth it to me.

soundguy

Nice internal shots of A.P.I 550b
« Reply #15 on: December 19, 2004, 09:45:41 PM »
If you look really hard you can buy a brand new API 550b for not very much more than that, just makes sense to buy a new one.  The api reissue of the 550A is waaaay more money than the B which has to be the most moronic thing Ive ever heard of.  Honestly, who the F cares if the switch is handwired or if it is PCB mount?  Honestly?  I would be shocked if they sound different, they MUST be using the same opamps for both.  It would have made sense to make the A cheaper than the B since it is three band, that would have beeen cool, who is gonna buy a more expensive three band EQ when you can get a 4 band with more points, more flexability that sounds exactly the same.  Talk about vintage hype, what a wierd decision for api to make.  I think I prefer the 550 over everything, whatever they were using for opamps back then, the 550's I have are way more mellow sounding than my 550a or b's.  I was suprised to see BA offer a new EQ that is priced identically to what you'd pay for original API equipment.  Wierd.

I have been wishing for a billion years that someone would offer somethig to fit the api form factor but SOUND DIFFERENT.  Ron, if you do an EQ, stick a totally different sounding opamp in there.  That would be really slick and could be a good $$$ maker if you did it right.  Some kinda ultra saturated  sounding opamp in there would kill.

dave

chips are good with dip...

Nice internal shots of A.P.I 550b
« Reply #16 on: December 19, 2004, 09:48:01 PM »
Am I missing something? What's an AD op amp?
Seth

The definition of insanity: "Hey, this thing could be really cool - if I had the money to fix it up, which I don't, but if I did it could be really cool - if I had the time, which I don't, but

tubejay

Nice internal shots of A.P.I 550b
« Reply #17 on: December 19, 2004, 09:49:29 PM »
Seriously, the only reason they used dual concentrics was to save space.  If we did a new version, there would be absolutely no reason to use 100 dollar a piece switches.  None.  Call me crazy, but I'd imagine the sound would be really really close, and who knows...maybe better.

soundguy

Nice internal shots of A.P.I 550b
« Reply #18 on: December 19, 2004, 10:00:25 PM »
analog devices.

I dont know what chip they put in there, but the output driver is built out of an analog devices chip.

if you are putting the EQ in a regular chasis, then no there would be no reason to use dual concentrics.   It would be a)a more expensive switch and b) harder to find cool knobs.  

dave

chips are good with dip...


 

Related Topics

  Subject / Started by Replies Last post
16 Replies
8534 Views
Last post May 30, 2016, 12:30:08 PM
by martthie_08
88 Replies
29355 Views
Last post April 18, 2015, 03:19:45 PM
by martthie_08
2 Replies
1479 Views
Last post February 03, 2010, 08:41:45 AM
by fluxivity
15 Replies
3354 Views
Last post June 24, 2010, 03:37:44 AM
by mulletchuck