Calrec PQ-1253 - how to rack them?

prinsnilsson · 12th January 2007, 06:42 PM

Hi!

First post here, been reading for a while and so many interesting people here, thanks.
Well, I got a pair of Calrec PQ-1253 for nothing, I will get the pin-out-schematics mailed to me, but I was wondering if anyone knows if these modules need other boards to work properly? Read somehwhere that they need two other boards in a chain to be able to work properly. On the other hand I read a description that said that you could just solder straight onto the pins if you know which is which.
Anyone with experience in these modules or similair ones?
Thanks in adavance!
/Mathias

LaChunkyStudio · 13th January 2007, 01:38 AM

Hi,

I have 8 of these babies. And I hung Lundahl 1517 transformers off the unbalanced outputs of all of them. Sounds great but I was told by someone on this forum that I should use a drive circuit in between the output of the module and the transformer. They are right as the output of the 1253 isn't designed to drive a naked transformer. However my modules still sound good (and I have tested them with a Lindos for freq response and an oscilloscope for ringing) - I haven't had time to build the drive circuits though I have a circuit diagram now - I will let the forum know how I get on when I finally find time to build the drive circuit.
In the meantime a Lundahl tranny will work just fine on the output.

prinsnilsson · 15th January 2007, 03:19 PM

Thanks!
Will try the Lundahl 1517 transformers, have a few of them in my studio actually :)
Let the board know if you get around building the drive circuit, would be more than happy to try it, if you want to, maybe you could pm me the drive circuit diagram and maybe I would find time to build them.
Cheers.

prinsnilsson · 6th November 2007, 06:43 PM

Does anyone know if the audio board Model OS2468 from Calrec is the one needed to drive the 1253 to get max gain out of them? It is fitted with 2x Lundahl 1517 but I can't find any info on which board was designed for which preamp.
If anyone knows, please let me know.

LaChunkyStudio · 8th November 2007, 04:05 PM

http://img.photobucket.com/albums/v1...lrecUA8000.gif

Try the top circuit.....

LaChunkyStudio · 8th November 2007, 04:09 PM

Sorry, that link doesn't work

Try this ......

calrec-pq-1253-how-rack-them-ll1517_output_stage_calrecua8000.gif

pulse_divider · 8th November 2007, 06:11 PM

I have a pair of these and had them professionally racked. They sound nice.

I also got a pair of DL1656 comp/limiters and put these in the same rack so that the pre outputs go directly into the comp inputs. The comp output driver does the job you're looking for and is transformer balanced... there are some on Ebay right now and they're really cool VCA based comps. The 2 modules fit together horizontally in a 19 inch rack and was able to fit 2 full channel strips in a 2U unit. There are unbalanced I/Os that break the signal path at each stage but I really only use the preamp inputs and compressor outputs.

The guy that did the racking job for me had a .pdf file posted on his website for a while with all the details and parts list. I can't seem to find it on the web anymore but I have a copy on my hard drive... PM me if you want me to e-mail it to you.

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12th January 2007, 06:42 PM	#1
prinsnilsson Gear Head Join Date: Jan 2007 Posts: 38	Calrec PQ-1253 - how to rack them? Hi! First post here, been reading for a while and so many interesting people here, thanks. Well, I got a pair of Calrec PQ-1253 for nothing, I will get the pin-out-schematics mailed to me, but I was wondering if anyone knows if these modules need other boards to work properly? Read somehwhere that they need two other boards in a chain to be able to work properly. On the other hand I read a description that said that you could just solder straight onto the pins if you know which is which. Anyone with experience in these modules or similair ones? Thanks in adavance! /Mathias

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13th January 2007, 01:38 AM	#2
LaChunkyStudio Gear nut Join Date: Jun 2006 Location: Glasgow, Scotland. Posts: 134	Hi, I have 8 of these babies. And I hung Lundahl 1517 transformers off the unbalanced outputs of all of them. Sounds great but I was told by someone on this forum that I should use a drive circuit in between the output of the module and the transformer. They are right as the output of the 1253 isn't designed to drive a naked transformer. However my modules still sound good (and I have tested them with a Lindos for freq response and an oscilloscope for ringing) - I haven't had time to build the drive circuits though I have a circuit diagram now - I will let the forum know how I get on when I finally find time to build the drive circuit. In the meantime a Lundahl tranny will work just fine on the output.

15th January 2007, 03:19 PM	#3
prinsnilsson Gear Head Join Date: Jan 2007 Posts: 38	Thanks! Will try the Lundahl 1517 transformers, have a few of them in my studio actually :) Let the board know if you get around building the drive circuit, would be more than happy to try it, if you want to, maybe you could pm me the drive circuit diagram and maybe I would find time to build them. Cheers.

6th November 2007, 06:43 PM	#4
prinsnilsson Gear Head Join Date: Jan 2007 Posts: 38	Does anyone know if the audio board Model OS2468 from Calrec is the one needed to drive the 1253 to get max gain out of them? It is fitted with 2x Lundahl 1517 but I can't find any info on which board was designed for which preamp. If anyone knows, please let me know.

8th November 2007, 04:05 PM	#5
LaChunkyStudio Gear nut Join Date: Jun 2006 Location: Glasgow, Scotland. Posts: 134	http://img.photobucket.com/albums/v1...lrecUA8000.gif Try the top circuit.....

8th November 2007, 04:09 PM	#6
LaChunkyStudio Gear nut Join Date: Jun 2006 Location: Glasgow, Scotland. Posts: 134	Sorry, that link doesn't work Try this ......

8th November 2007, 06:11 PM	#7
pulse_divider Gear maniac Join Date: Apr 2004 Location: Akron, OH Posts: 265	I have a pair of these and had them professionally racked. They sound nice. I also got a pair of DL1656 comp/limiters and put these in the same rack so that the pre outputs go directly into the comp inputs. The comp output driver does the job you're looking for and is transformer balanced... there are some on Ebay right now and they're really cool VCA based comps. The 2 modules fit together horizontally in a 19 inch rack and was able to fit 2 full channel strips in a 2U unit. There are unbalanced I/Os that break the signal path at each stage but I really only use the preamp inputs and compressor outputs. The guy that did the racking job for me had a .pdf file posted on his website for a while with all the details and parts list. I can't seem to find it on the web anymore but I have a copy on my hard drive... PM me if you want me to e-mail it to you.