G-PULTEC problems, please help!

[djfatum]

I wonder about the power of a single transformer 50VA
second  220 v  & 9v  whether it is a good solution for stereo ??

https://pcbgrinder.com/index.php?route=product/product&path=60&product_id=122

Andrzej

 

[weiss]

I wonder about the power of a single transformer 50VA
second  220 v  & 9v  whether it is a good solution for stereo ??

https://pcbgrinder.com/index.php?route=product/product&path=60&product_id=122

Andrzej

you need these specs: Primary: 2 x 115v (230v) / Secondarys: 220V 0,1A / 9V 2,5A / 5V 0,5A

e.g.: http://www.don-audio.com/g-pultec-power-trafo-sec-220v-9v-5V

 

[Mraihala]

Hello!

Is it possible to use Lundahl LL1540 in this?

Best,

Mikko

 

[gyraf]

Is it possible to use Lundahl LL1540 in this?

Not really - it has way too high copper resistance for low-impedance stuff like this.

Jakob E.

 

[MicDaddy]

What is the expected (any?) insertion loss with the eq in "bypass"?  I thought it had enough gain to be minimal but am now experiences some lower level going through one gpultec.

 

[gyraf]

Depends on actual tube gain.

We are using the raw gain of the tube, no feedback.

I've seen figures from -3 to +2dB

Jakob E.

 

[elziel]

Hi everyone !

I've just finished my g pultec and it's so fantastic sounding unit. This topic was very helpfull in my build, but there is one problem that i have occured in my build  that wont let me sleep... is it normal that all freqency selector switches are popping when switched?

 

[weiss]

Hi everyone !

I've just finished my g pultec and it's so fantastic sounding unit. This topic was very helpfull in my build, but there is one problem that i have occured in my build  that wont let me sleep... is it normal that all freqency selector switches are popping when switched?

is it a loud pop or a click? You could check the direction of all the electrolytic caps.

 

[kante1603]

Hi everyone !

I've just finished my g pultec and it's so fantastic sounding unit. This topic was very helpfull in my build, but there is one problem that i have occured in my build  that wont let me sleep... is it normal that all freqency selector switches are popping when switched?

MBB or BBM switches?


Best,


Udo.

 

[elziel]

Hi everyone !

I've just finished my g pultec and it's so fantastic sounding unit. This topic was very helpfull in my build, but there is one problem that i have occured in my build  that wont let me sleep... is it normal that all freqency selector switches are popping when switched?

MBB or BBM switches?



Best,


Udo.

BBM i think.

 

[gyraf]

then yes, normal

 

[SKJGProject]

i have bought a unit several years ago from a quite experienced builder from here...unit was damaged during shipping (transformers were to heavy to survive the rude handling from the dhl guys) but fortunately only mechanical mounting got loose.

due to the veroboard build and my lack of experience i can't use this unit until now  because i get a quite high level hum/buzz in one of the two channels.

this is a pic of the inside, maybe someone can figure out some problems with untwisted wires that should be twistes or trafo placement etc...otherwise i have to sell this unit to someone who might be able to fix it!

 

[gyraf]

Loosen toroid power transformer bolt slightly, and turn the transformer while listening for the spot where hum is lowest.

Probably when the wire breakout point of the transformer is pointing furthest away from your input transformers (as it's here the most stray field exits the toroid).

Jakob E.

 

[MicDaddy]

Using one of my G-Pultecs, all but one of the low frequency positions work.

When switched to this problematic position the overall output level becomes HUGE and there is no low end "filtering" happening.  Is it possible that there is no attenuation happening and at the same time being amplified by the makeup?

Have yet to open it up.  It was working just fine for years. 

Guesses?  Failing switch, open/shorted cap?

 

[gyraf]

One capacitor not connected through switch to circuit.

 

[MicDaddy]

Thank you Jakob, I'll post back what I find. 

I've never heard a real Pultec, but as far as equalizers go I enjoy these units very very much.

 

[Shiftworker]

I have 2 GPultecs built by someone in November. He got 99% correct ( ithink) but got very lazy with the soldering, heatsink etc.
I ironed out the basic problems by finding the bad joints and a much bigger heatsink. Now [Allen Heath 62 --> Patchbay --> L / R pultecs --> Patchbay --> interface...]. One minute the signal is happy and level, then one ch will dip with bass roll-off. I wait a bit and it sorts itself out. 
It is shorting somewhere, but I aint no engineer and don't have no more time to deal with it. 3 months is my limit.

Buider rang loads of times but with lame answers.

If anyone is in London and could help, obviously with bench time ££

 

[gyraf]

double-check heater voltage!

 

[darkus]

Hi! Just wired up the first of my two g-pultecs and im getting very little gain out of this. It seems to work as it should otherwise, and it sounds good. Its just that i have about 65dB gain loss! The unit is dead quiet too, no hiss or hum, i just need to use a preamp to add gain after the eq. Bypass mode has the same, little amount of gain. The in-going signal was a -8dB RMS mastered track peaking at -6 so there was definately enough gain going in.

Im using Edcor WSM transformers, 600:600 for input and 15k:600 for output. Im thinking if i just wired them wrong? Both are wired like this:

LL5402            Edcor

2                                1
5                                4
7                                5
10                              8

Ive connected LL5402 pad 3 to the shell of edcor trafo.

Ive measured voltage before output cap and it shows me 122V dc so it should be good right?

 

[Deepdark]

too low inductance at the transformer?