Purusha
Well-known member
The usual 20db for the mastering environment would be nice. 0/+20db
31267 optimal wiring in the solid state Pultec
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Purusha
Well-known member
Hi, it's me again, please turn off your newbie alert :green:
I have wired my Pultecs by following those dots above but still somewhere down the line
my phase reversed on the output of the unit. Can I reverse the polarity anywhere in the circuit
or is there any special rule? I can do it in the input or in the output of the 31267 or later after
the EQ Pultec part before or after the B283 gain stage. I reversed it for test on the input of the
31267 and sounds again in phase but I am not sure if this really OK. Have I now wired the input
iron in a wrong way? Is this bad in any way?
I have wired my Pultecs by following those dots above but still somewhere down the line
my phase reversed on the output of the unit. Can I reverse the polarity anywhere in the circuit
or is there any special rule? I can do it in the input or in the output of the 31267 or later after
the EQ Pultec part before or after the B283 gain stage. I reversed it for test on the input of the
31267 and sounds again in phase but I am not sure if this really OK. Have I now wired the input
iron in a wrong way? Is this bad in any way?
Purusha
Well-known member
OK, thanks for the tip.
Well, when I wire the 31267 -6db I get back enough gain with B283s,
but if I go -13db it's just not enough... I am 3db short with Sowter 8751
and even more with Fabio's Lynx LO1166 type transformers. It seams
Sowter gives more gain.
BTW, how can I track down the positive line through the circuit without the scope. Is it possible with ammeter?
Well, when I wire the 31267 -6db I get back enough gain with B283s,
but if I go -13db it's just not enough... I am 3db short with Sowter 8751
and even more with Fabio's Lynx LO1166 type transformers. It seams
Sowter gives more gain.
BTW, how can I track down the positive line through the circuit without the scope. Is it possible with ammeter?
Ok, well you have an impedance-matched input at the Pultec input which should make you lose around 6dB. Then you've got your loss at the 31267 too. Then there is the loss of the filter circuit itself (which Jakob discussed).
I'm not sure about the input impedance of the BA283 - I assume it is high impedance? I've never checked, but I guess the interface will be bridging.
Did you calculate how much gain you are getting from the BA283 board?
What ratio do you have the output transformers set at?
No! :razz:
You really need a scope I think - it is only balanced before the input and after the output, so you can't go far wrong wth phase unless the boards themselves flip polarity.
I'm not sure about the input impedance of the BA283 - I assume it is high impedance? I've never checked, but I guess the interface will be bridging.
Did you calculate how much gain you are getting from the BA283 board?
What ratio do you have the output transformers set at?
No! :razz:
You really need a scope I think - it is only balanced before the input and after the output, so you can't go far wrong wth phase unless the boards themselves flip polarity.
Purusha
Well-known member
According to Fabio's schematics for his Neve driver boards I can squeeze 30-35db of gain max.
I used resistors to get maximum out which is fine if i use the -6db wiring on 31267. The thing is I
installed the true bypass with relays instead of Gyraf bypass which is done just before the EQ.
Yeah, this would also I like to know :grin: Fabio just gave me the info how to wire his Neve
transformers and Rob gave me the info how to wire the 8751. That is all. Maybe I should investigate
this a little.
LL makes many a [1:1]ll[2:2]
Just steal a data sheet for hookup purposes.
Don't make me do it otherwise I'm gonna get pissed.
:razz:
Just steal a data sheet for hookup purposes.
Don't make me do it otherwise I'm gonna get pissed.
:razz:
Purusha
Well-known member
Fabio's Lynx iron info
Input Z: 600R, Output Z: 600R/150R
BW: 5Hz to 87kHz
Ratio: 1:1/1:2
Max output level: +30dBu @ 600R load
...
Input Z: 600R, Output Z: 600R/150R
BW: 5Hz to 87kHz
Ratio: 1:1/1:2
Max output level: +30dBu @ 600R load
...
Purusha
Well-known member
Sowter 8751
Ratio 1:1.5.
Max output level +30 dBu....
I just compared the sound of both and I prefer Lynx. More open highs and tight
bottom. I wonder how will vintage Marinair LO1166 sound compared to
those two? Probably not so modern and in your face like Lynx.
Ratio 1:1.5.
Max output level +30 dBu....
I just compared the sound of both and I prefer Lynx. More open highs and tight
bottom. I wonder how will vintage Marinair LO1166 sound compared to
those two? Probably not so modern and in your face like Lynx.
You guys hear a differenence on the outputs?
I would imagine the input transformers would change the sound more, but a real test is worth a thousand cj's.
:grin:
I would imagine the input transformers would change the sound more, but a real test is worth a thousand cj's.
:grin:
Purusha
Well-known member
I made two stereo Pultecs with exactly the same components but the output transformers and there is a difference in the sound :wink:
For reals?
Same tubes?
Wow. This is cool. Posting from Stanford Terman Eng Lybrary on the "Pubic Kiosk."
Terman was the guy who talked Bill Hewitt and Bill Packard into not moving back East and selling out to the Big Companies, like RCA and GE and Phillips.
Instead, he encouraged them to start their own buisness and the result was Silly Con Valley, where I am trapped.
Off to research xfmr's ferromagnetism, and Au Sputtering, need anything?
Cool. They have 36 CD's with the Feynman Lectures.
Same tubes?
Wow. This is cool. Posting from Stanford Terman Eng Lybrary on the "Pubic Kiosk."
Terman was the guy who talked Bill Hewitt and Bill Packard into not moving back East and selling out to the Big Companies, like RCA and GE and Phillips.
Instead, he encouraged them to start their own buisness and the result was Silly Con Valley, where I am trapped.
Off to research xfmr's ferromagnetism, and Au Sputtering, need anything?
Cool. They have 36 CD's with the Feynman Lectures.
Purusha
Well-known member
Maybe I should say Nevetecs :green:
Oh yeah, this is where the internet started also, right here on the campus.
I picked up on some really cool books down here.
One of them said that you should paralell the pri and series the sec to get a step up of 0.9:1
since the true turns ratio of the 31267 is 1.8:1
There is still plenty of inductane, about 15 henries.
cj
I picked up on some really cool books down here.
One of them said that you should paralell the pri and series the sec to get a step up of 0.9:1
since the true turns ratio of the 31267 is 1.8:1
There is still plenty of inductane, about 15 henries.
cj
Purusha
Well-known member
Can I do this in my Nevetecs? My EQ circuit desires 600Ohm load on the way in. Isn't this wiring for the 2K4/2K4 - 0db?
Who won the Buick Open Golf Tourney at Tore Pines, San Diego, yesterday?
Purusha
Well-known member
I quit :?
Tiger Woods
radiance
Well-known member
[quote author="CJ"]Tiger Woods[/quote]
Well, that was'nt to hard was it? It's about the only "golf name " I know.....
Well, that was'nt to hard was it? It's about the only "golf name " I know.....
Purusha
Well-known member
OK, maybe I should ask him regarding the wiring :green:
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