Frank's Pultec Support

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gyraf

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quote from that page:

Iam sure I and Nino can make some inductors for this project. Because of the additional frequencies we need a custom inductor... this is available at sowter but they cost an arm... iam sure we can offer inductors for the half of an arm.
 

seavote

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anyone know of sources for the transformers edit: inductors used in the mid-pultec filter boards available from gustav.
 

ChrioN

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No transformers in Franks mid freq pultec. Its solidstate from beginning to end.

seavote said:
anyone know of sources for the transformers used in the mid-pultec filter boards available from gustav.
 

seavote

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i've been in contact with aaron at don-audio.
http://don-audio.com/Spule-Equalizer-DIY-Projects-312155783926-20-Tolerance

he says if we can get 10+ orders  he will make up a batch of inductors for the MEQ project. if your doing stereo like me thatonly 5+ members. anyone interested?
 

seavote

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i just saw this:
http://www.diygallery.de/DIYsites/inductor.html
it doesnt look too intimidating.  not as intimidating as paying for 8 custom inductors from sowter or don-audio + shipping to US.
chrion, i think i would be interested when i start my project (most likly a long way off, this project is 3 back on my DIY list)  depending on price. i know you need to be compensated for your time and effort. this might also make it more appealing to DImyself. i'll PM you.
 

fallout

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ChrioN said:
No transformers in Franks mid freq pultec. Its solidstate from beginning to end.

seavote said:
anyone know of sources for the transformers used in the mid-pultec filter boards available from gustav.

If you're not using Frank's makeup gain PCB, I'm assuming you would use the same transformers as the regular PEQ (Triad HS 56/66 or equivalent). Chrion, I might be interested in custom wound inductors. How much do you plan on selling them for? Cinemag also makes inductors for this project for a decent price (I was quoted $22.38 for each inductor). Being in the US that might be the cheapest/easiest route to go.

The Cinemag part #'s are 2251-1, 2251-2 and 2251-3

-jay
 

ChrioN

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If you can get inductors for 22 dollars from a company like cinemag, I would definitely get my inductors from them. Whats their tollerance?

fallout said:
ChrioN said:
No transformers in Franks mid freq pultec. Its solidstate from beginning to end.

seavote said:
anyone know of sources for the transformers used in the mid-pultec filter boards available from gustav.

If you're not using Frank's makeup gain PCB, I'm assuming you would use the same transformers as the regular PEQ (Triad HS 56/66 or equivalent). Chrion, I might be interested in custom wound inductors. How much do you plan on selling them for? Cinemag also makes inductors for this project for a decent price (I was quoted $22.38 for each inductor). Being in the US that might be the cheapest/easiest route to go.

The Cinemag part #'s are 2251-1, 2251-2 and 2251-3

-jay
 

mitsos

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I've been talking to Altran about some trafos for the group-buy 312 boards... They make excellent trafos, and also do inductors, and I was going to ask them to make a pair of IRON CORE inductors for me... I don't know what cinemag uses in their pultec inductor, but I'd like to avoid ferrite (not that it's bad, but iron core is supposed to sound better when it saturates (repeating what I've read, I haven't done any tests). I'm going to call them tomorrow about the trafos and will see what they can do my inductors.  I'll post back when I know, and if people are interested in that, it should be inexpensive. Off the top of my head, price for one inductor is about $20... again, I'd be interested to know if Cinemag uses ferrite or iron.  Are people looking for MEQ stuff only, or both PEQ and MEQ? And if PEQ, is it the extanded or normal version?  I'm looking for PEQ, and leaning toward the extanded/enhanced, whatever it's called.

Ideally of course, someone would make a toroidal inductor.... I think DrPat made some himself..
 

lassoharp

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mitsos said:
I've been talking to Altran about some trafos for the group-buy 312 boards... They make excellent trafos, and also do inductors, and I was going to ask them to make a pair of IRON CORE inductors for me... I don't know what cinemag uses in their pultec inductor, but I'd like to avoid ferrite (not that it's bad, but iron core is supposed to sound better when it saturates (repeating what I've read, I haven't done any tests). I'm going to call them tomorrow about the trafos and will see what they can do my inductors.  I'll post back when I know, and if people are interested in that, it should be inexpensive. Off the top of my head, price for one inductor is about $20... again, I'd be interested to know if Cinemag uses ferrite or iron.   Are people looking for MEQ stuff only, or both PEQ and MEQ? And if PEQ, is it the extanded or normal version?  I'm looking for PEQ, and leaning toward the extanded/enhanced, whatever it's called.

Ideally of course, someone would make a toroidal inductor.... I think DrPat made some himself..



I'm not positive but I believe Cinemag uses ferrite EI as does Sowter.  Like you I was looking for a torroidal type with a powdered iron core for the supposed saturation properties.

It can be tricky finding a small quantity vendor for the raw iron cores.  Maybe check this thread for more extensive info:

http://www.groupdiy.com/index.php?topic=25482.0
 

Script

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seavote said:
i've been in contact with aaron at don-audio.
http://don-audio.com/Spule-Equalizer-DIY-Projects-312155783926-20-Tolerance

he says if we can get 10+ orders  he will make up a batch of inductors for the MEQ project. if your doing stereo like me thatonly 5+ members. anyone interested?

Might be interested. With the Cinemags there are slight differences in values, but should be okay, I guess. Though 200mH versus 280mH is defo more than 20% "tolerance"...

Frank's MID-EQ needs these three inductors (values) per channel:
120mH, 200mH, 420mH, 520mH
34mH, 61mH, 100mH, 145mH, 277mH, 420mH
477mH, 625mH

The Cinemags are:
[2251-1]: 520mH, 420mH, 280mH, 120mH
[2251-2]: 420mH, 277mH, 145mH, 110mH, 61mH, 34mH
[2251-3]: 625mH, 475mH

Don's inductors are iron core? And he sells for 16 euros/piece?

Script




 

fallout

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If you are going to get iron core inductors, count me in.. I'm doing both a PEQ (Frank's Enhanced) and MEQ (Frank's PCB).

-jay
 

seavote

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i'm leaning towards the cinemag for the midEQ inductors. if mitsos comes up with something from altran for the enhanced pultec i'll go for that.  don audio sells inductors for this(enhanced pultec) for 16 euro  20% tolerance and 24 euro 10%. shipping to new york is almost $25 US so that gets expensive

i'd like to make 2 channels.  enhanced and mid pultec in one unit. can i connect one passive board directly to the other?  
will one amp section per 2 board channel do or should i amplify befor sending the signal from one board to another?  
thanks for any help. i may have been here for a while but i still have a great deal to learn.
 

seavote

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bump?  anyone?

fallout i've emailed cinemag 2Xs and they have not replied. can you post the price per inductor?
thanks
 

benlindell

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Cinemag can be hard to get emails from, it's best to call them. As I recall their inductor prices are reasonable.
 

mitsos

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I'm still working on this.. Since we're trying to close up the 312/990 trafo group buy atm, I am giving priority to that, since there are a lot of people involved, but rest assured, I will one day have my non-ferrite pultec inductor, and if all goes well, it'll be a moly-permalloy toroid. I think I am set on the enhanced (vs original) pultec as well, so that's what I'm working on. Like most things, its definitely possible, just don't know what kind of price we're going to get...but I will definitely post back, since the more we buy, the cheaper they get per.

I'd guess the MEQ inductors would cost about the same as the PEQ, so once we know that price, we can go ahead with this one too.  I don't know if the originals were toroids, but once we know the PEQ price, we can decide if it's worth it to go this route.... there're 3 inductors in that one..

seavote... ditto on calling cinemag.. I've never gotten an email response from them. usually you'll get tom R on the phone who likes to talk trafos, it's like a free lesson!
 
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