ding

Re: G-PULTEC problems, please help!
« Reply #480 on: February 15, 2014, 09:57:18 PM »
This is what I ended up doing.
« Last Edit: February 15, 2014, 10:01:50 PM by ding »


Re: G-PULTEC problems, please help!
« Reply #481 on: February 19, 2014, 04:54:20 AM »
Hello guys,

I plan to make 2 G-Pultec units. I will buy PCB at PCB Grinder but I need some details about capacitors:

- What's lead spacing for 3n3, 6n8 etc ? And for the 330n, 470n, 4u7 etc ? Is it 7.5mm and 10mm ?
- Wich kind of caps I need ? Wima MKS2 ? MKS4 ? What is the best ?
- What is the voltage for small caps (3n3 to 100n) ? 63v ? And 250v the others ?

Last question: Where I can find 3n3, 6n8 and 12nf caps in Europe ? Can't find @ Farnell or RS !

Thanks for your help :)

ding

Re: G-PULTEC problems, please help!
« Reply #482 on: February 19, 2014, 08:36:59 AM »
Hello guys,

I plan to make 2 G-Pultec units. I will buy PCB at PCB Grinder but I need some details about capacitors:

- What's lead spacing for 3n3, 6n8 etc ? And for the 330n, 470n, 4u7 etc ? Is it 7.5mm and 10mm ?
- Wich kind of caps I need ? Wima MKS2 ? MKS4 ? What is the best ?
- What is the voltage for small caps (3n3 to 100n) ? 63v ? And 250v the others ?

Last question: Where I can find 3n3, 6n8 and 12nf caps in Europe ? Can't find @ Farnell or RS !

Thanks for your help :)

The lead spacing is in Don Audio's excel file. What WIMA sounds best is a never ending debate. Filter caps can be 63v and up. good luck.
« Last Edit: February 19, 2014, 08:43:11 AM by ding »

Re: G-PULTEC problems, please help!
« Reply #483 on: February 19, 2014, 09:59:53 AM »
Ok thank you ding.

Anyone know where I can find the 3n3, 6n8 and 12nf in France or Europe ? Thanks

EDIT: is it better to use Styroflex ? I've found the 3n3, 6n8, 12 and 18 in France ! And it's better to use resistors like Vishay CMF55 series ?
« Last Edit: February 19, 2014, 11:11:28 AM by spudstyle »

dipfrik

Re: G-PULTEC problems, please help!
« Reply #484 on: February 19, 2014, 07:20:09 PM »
Mouser ;)

 3n3  = 80-PHE450MK4330JR17T
 6n8 = 505-FKS36800/100/10P
 12nf = 5989-250V.012-F

Cheers, Sven

ding

Re: G-PULTEC problems, please help!
« Reply #485 on: February 20, 2014, 09:41:39 AM »
Ok thank you ding.

Anyone know where I can find the 3n3, 6n8 and 12nf in France or Europe ? Thanks

EDIT: is it better to use Styroflex ? I've found the 3n3, 6n8, 12 and 18 in France ! And it's better to use resistors like Vishay CMF55 series ?

Give them a try. I personally like wima on the low and orange drop on the high but it is DIY so give it a go.

Re: G-PULTEC problems, please help!
« Reply #486 on: February 21, 2014, 03:38:18 AM »
Ok, so if I want something sweet on the high, wich is better ? Wima, Orange drop or Styroflex ? I can't try every caps, not enough money :(

EDIT: do you think Cinemag CML-150T is better sounding than Toko inductors ? I just need to change some caps but it's not a problem.
« Last Edit: February 21, 2014, 06:57:55 AM by spudstyle »

ding

Re: G-PULTEC problems, please help!
« Reply #487 on: February 21, 2014, 09:46:33 AM »
Ok, so if I want something sweet on the high, wich is better ? Wima, Orange drop or Styroflex ? I can't try every caps, not enough money :(

EDIT: do you think Cinemag CML-150T is better sounding than Toko inductors ? I just need to change some caps but it's not a problem.

What sounds better depends on individual taste. I cannot/will not go into that. You will just need to experiment and find what you like. that is the best part of DIY, else just buy a used pultec from evilbay and call it a day. As far as inductors go there is something to be said about a multi-tap inductor with the proper ferrite. My taste right at this moment is that I like WIMA on the lows, orange drop on the highs, and custom inductor (hand wound or other wise) but that is what sounds good to my ears right now. Winding your own multi-tap is easy if you have a meter that measures in mH. I have built one with toko, one with hand wound, and one with cinemag and I do prefer the hand-wound/cinemag but that could just be mystical self mental masturbation than anything else. I thought toko sounded pretty good too. If you are going the cinemag route you need to call Cinemag and ask them to wind you a G-Pultec inductor 22,69,169,269. All in all, if you just use Wima and toko and everything thats in the BOM you will have a nice sounding piece of equipment that you will enjoy for many years. Don't get caught up too much into what caps are good. those are things that are not important. Use Polystyrene, polypropylene or polyester for the filter and audio portions of the main board and you will get a good sound.   ;D
« Last Edit: February 21, 2014, 09:54:55 AM by ding »

APL

Re: G-PULTEC problems, please help!
« Reply #488 on: February 23, 2014, 10:31:40 AM »
I also used mixture of WIMA and orange tops. I bought from Banzai Music in Berlin who had a good range.

However I found it difficult getting all WIMAs with correct lead spacing to fit  board. The WIMA leads are also very short and you cannot always bend them to fit. Also the larger value WIMAs I bought were too wide to fit in the space.

I also need to paralell some orange tops to get correct values

The ideal WIMAs and orange tops may be out there but I didnt find them.

Re: G-PULTEC problems, please help!
« Reply #489 on: February 23, 2014, 03:13:47 PM »
Thanks for your answers guys. I found all I need except the 2u2 in 7.5mm. My BOM is ok :)

Do you know if the original frequencies knobs exist in chinese model ? I found the original but it's $10 for a knob ! I found all other knobs, volume, off/on and the chickenhead (Tube-tech style no dakaware).


ding

Re: G-PULTEC problems, please help!
« Reply #490 on: February 23, 2014, 08:41:14 PM »
no problem  ;) I love old knobs so mine are all dakaware. on my last one I spent $120 just on knobs.  :o enjoy your new toy.

Re: G-PULTEC problems, please help!
« Reply #491 on: February 26, 2014, 04:53:06 AM »
I got a new question :)

I want to change some frequencies on the lows. I've seen that we have 20-25-30-40-60 and 100 Hz but I don't want the 20 & 25 Hz, I want to make something like 30-40-60-80-100 and 120 Hz. How can I calculate the frequencies on this filter ? I understand how to calculate the Hi filter (LC) but not the Lo :/
Sorry, I'm not electronician ^^

gyraf

Re: G-PULTEC problems, please help!
« Reply #492 on: February 26, 2014, 05:13:59 AM »
The frequencies (on all but HI-Boost) are proportional to the capacitors, as they are first order RC filters. Larger capacitors, lower frequencies. Try out some, and see what you like.

Not much to be gained IMO by changing frequencies, that's not where the magic works...

Jakob E.
..note to self: don't let Harman run your company..

djob

Re: G-PULTEC problems, please help!
« Reply #493 on: March 05, 2014, 06:37:02 AM »
hi all!
money saving question...
here it's 230v mains power, and i happen to have a 230v:6.3v valve transformer for the heater, so can i skip buying the stacked transformers and just run straight from the mains power acording to rest of the gpultec psu schematic.

cheers :)

Harpo

Re: G-PULTEC problems, please help!
« Reply #494 on: March 05, 2014, 08:46:01 AM »
money saving question...
here it's 230v mains power, and i happen to have a 230v:6.3v valve transformer for the heater, so can i skip buying the stacked transformers and just run straight from the mains power acording to rest of the gpultec psu schematic.
Brilliant approach against overpopulation. :o
Just don't run straight from mains power.
A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools.  -Douglas Adams

Re: G-PULTEC problems, please help!
« Reply #495 on: March 05, 2014, 09:07:00 AM »
The frequencies (on all but HI-Boost) are proportional to the capacitors, as they are first order RC filters. Larger capacitors, lower frequencies. Try out some, and see what you like.

Not much to be gained IMO by changing frequencies, that's not where the magic works...

Jakob E.

Ok but don't understand how to calculate the low filter. What caps values I need if I want 20-30-40-60-80-100 Hz in the flow filter ? Thanks

ding

Re: G-PULTEC problems, please help!
« Reply #496 on: March 05, 2014, 10:53:59 AM »
The frequencies (on all but HI-Boost) are proportional to the capacitors, as they are first order RC filters. Larger capacitors, lower frequencies. Try out some, and see what you like.

Not much to be gained IMO by changing frequencies, that's not where the magic works...

Jakob E.

Ok but don't understand how to calculate the low filter. What caps values I need if I want 20-30-40-60-80-100 Hz in the flow filter ? Thanks

https://www.google.com/#q=RC+filters+calculator  :P

Re: G-PULTEC problems, please help!
« Reply #497 on: March 06, 2014, 02:20:08 AM »
The frequencies (on all but HI-Boost) are proportional to the capacitors, as they are first order RC filters. Larger capacitors, lower frequencies. Try out some, and see what you like.

Not much to be gained IMO by changing frequencies, that's not where the magic works...

Jakob E.

Ok but don't understand how to calculate the low filter. What caps values I need if I want 20-30-40-60-80-100 Hz in the flow filter ? Thanks

https://www.google.com/#q=RC+filters+calculator  :P

I know google and I got a calculator but I don't understand the filter in the schematic. I'm not electronician. Where is the filter ? This is the filter between 10k resistor and "2u2-1u-680n-etc" ? Please explain me, I don't ask you to do the job, I just want to understand :)
if you think otherwise, it's because my english sucks lol

who

Re: G-PULTEC problems, please help!
« Reply #498 on: March 07, 2014, 11:17:11 AM »
inductors and the caps make the filter.

Don
Inductors, Power Trafos, Knobs, Trafo shielding sheets, Frontpanels
http://don-audio.com
https://www.facebook.com/DonAudioShop
Visit us :)

gyraf

Re: G-PULTEC problems, please help!
« Reply #499 on: March 08, 2014, 02:06:41 AM »
..but the inductors are only involved in the high-boost section.

spudstyle - it is all in the schematic. If the schematic does not make sense to you, try the mentioned empiric approach:

Quote
Larger capacitors, lower frequencies. Try out some, and see what you like.

Jakob E.
..note to self: don't let Harman run your company..


 

Related Topics

  Subject / Started by Replies Last post
4 Replies
2076 Views
Last post August 16, 2004, 02:08:36 PM
by frob
4 Replies
2192 Views
Last post November 13, 2004, 10:51:40 AM
by Adky
2 Replies
2507 Views
Last post May 23, 2006, 04:51:14 PM
by rubric
2 Replies
1935 Views
Last post November 17, 2006, 05:25:08 PM
by carloff