Help Pls - Coupling Capacitor - diyAudio
Go Back   Home > Forums > Source & Line > Analog Line Level

Analog Line Level Preamplifiers , Passive Pre-amps, Crossovers, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 15th December 2011, 02:12 AM   #1
tony Ma is offline tony Ma  United States
diyAudio Member
 
Join Date: Feb 2011
Smile Help Pls - Coupling Capacitor

I have JP200 and just solved the problem that I got (excessive noise and un-balance between the channel)
Now I am thinking to change the capacitor

I am leaning on these capacitor only

Mundorf Supreme Silver oil

Janzten

Auricap

The capacitor that I need is .47uf (Coupling Capacitor) and 1uf and 2uf

Due to the budget, I am thinking to use .47 with Mundorf and remaining using Auricap.

Here is the schematic
http://analogmetric.com/download/JP2...0Schematic.pdf

Any input pls....

tks
  Reply With Quote
Old 15th December 2011, 04:25 AM   #2
Previously: Kuei Yang Wang
 
Join Date: Nov 2002
Hi,

Quote:
Originally Posted by tony Ma View Post
I have JP200 and just solved the problem that I got (excessive noise and un-balance between the channel)
Now I am thinking to change the capacitor
The original sound of Jadis equipment is a combination of the specific circuit features AND of the passive parts. These are not common audiophile types.

To help you it would be good if could state what capacitors you use right now and what kind of change in sound quality you desire.

Quote:
Originally Posted by tony Ma View Post
Mundorf Supreme Silver oil

Janzten

Auricap
They all sound to my ears very much like any generic plastic cap's with little to recommend them over simple industrial film capacitors. They use metalised plastic film as well.

In all cases I prefer even generic Arcotronics KP1.72 series capacitors over these, which is a very cheap industrial foil & film capacitor (possibly discontinued, I use better stuff now).

Among my best liked capacitors are in order of preference:

Silver Foil & any plastic film (not PIO)
Copperfoil & any plastic film (not PIO)
Tinfoil & Teflon (e.g. VH Cap's)
Tinfoil & Polystyrene (e.g. MIT RT Series and old stock German KS Capacitors)
Tinfoil & Polypropylene (e.g. Mundorf M-Cap Zn etc.)
Aluminum Foil Foil & Film Capacitors (e.g. old stock ERO KP or Arcotronics KP)

Quote:
Originally Posted by tony Ma View Post
This is not really a copy of the JP200. It looks like a copy of a supposed copy of JP200 sold a decade or so ago by a Hong Kong Shop. The HK Shop already simplified and changed the original JP200 design to make it easier to DIY, it seems this shop has made more changes.

Real Jadis has many capacitors in parallel on the output, including Mylar type metalised (often Orange Drops) and MKP (I have seen even SCR and orange drops there) and one smaller value Foil & Film Type (various).

Total capacitance is usually larger than 2uF, I have often seen values around 6uF.

You can reduce the capacitor marked as 0.47uF to 0.1uF value without ill effects (this is seen on some Jadis Preamps too) or even lower if you increase the value of the 470K resistor after the capacitor (not Jadis but mine).

The output capacitor can be another value if you are only going to use tube amplifiers with high input impedance, but it is borderline in terms of size for some Solid State Amplifiers and too small for use with Jeff Rowlands and other very low input impedance Solid State Amplifiers.

You also need to look at the 1uF input Capacitor. This too has a large effect on sound quality. Jadis interestingly often used Mylar there. Go figure.

The electrolytic capacitors in the Pre's supply lines also will have an impact...

You need to consider if you want Jadis sound as original Jadis or if you want to do your own thing.

In the second case my first change would probably to use a 12AU7 or similar for T3. I would remove R12 and make R8 3.3K/1W and R11 33K/3W (needs C4 = 3.3pF).

I would likely change R6 and R9 to 3M3 and use 10nF non-magnetic silver mica capacitors for C1 & C4.

I would use a single large tinfoil output coupling capacitor for C5 (as large as I can afford) and another 10nF Silver Mica (non magnetic is very important) for the C3 bypass.

BUT, the resulting line stage would not be a Jadis JP200 and what I like in sound may not be what you like.

In fact, personally REALLY I would probably simply throw that JP200 imitation board out and build a Kondo M7 Linestage with a single 5687 tube into the case instead...

Ciao T
  Reply With Quote
Old 15th December 2011, 04:02 PM   #3
tony Ma is offline tony Ma  United States
diyAudio Member
 
Join Date: Feb 2011
Hi Thorsten, thank you for the input

I don't have a skill like you, I am just a beginner to build this pre-amp.

What I am trying to reach here to make the sound more open.

Currently I have Solen Capacitor on it.

Here is my settings, CD - Tera DAC (i did modify it by change the capacitor) - Jp 200 - B&K st-140

tks
  Reply With Quote
Old 15th December 2011, 04:58 PM   #4
Previously: Kuei Yang Wang
 
Join Date: Nov 2002
Hi,

Quote:
Originally Posted by tony Ma View Post
Currently I have Solen Capacitor on it.
Then, with respect, do not expect major improvements from the Cap's you listed. There is a nice overview of the different Cap's you can get on a Website linked with Tempo Electric (aka Arthur Loesch and Joseph Levy):

The Great Capacitor Shoot-Out

I am not in 100% agreement on all the items, but what is written is mostly accurate IME.

They have major outliers in the Tinfoil Cap category, generally citing a "glare". There are reasons for this in their setup, however I think this is overemphasised.

I personally use Tinfoil Cap's extensively, but they do need for some reason quite a bit of time to "settle in" or "burn in" and can sound spitty and glarey inbetween.

Of course take all this with a grain of salt, there are those here who happen to not trust their ears and who insist that subjective differences between capacitors and "capacitor burn-in" are all just pigments of their imaginations and hence the must be true of everyone else...

You could try to find some nice large value Wima FKP (they used to make them in as high as 0.22uF - I have them stashed) and apply them in the two position in input and coupling between stages, using a third one in parallel with the output cap.

Ciao T
  Reply With Quote
Old 1st October 2013, 11:37 AM   #5
diyAudio Member
 
Join Date: Jan 2011
what really happens with all the jadis sound is they sound slow, dark and with no treble and an really bass , but like all the things , are people that like, i don't,
i think that the only thing that jadis make moreanless is the boxes, they look very well, a few days ago i see an review of jadis se300b, its really unthinkable,
how an thinks coast 12k , have all those things wrong, the site is jadis 300b reformed, its really amasing , so this people in jadis don't really now nothing about project, music, nothing, use philips capacitors in audio amplifiers, things that coast 1 peny, and take 12k ????

the best equipments that i hear and now are, kondo , and wiregain.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Coupling capacitor selection DcibeL Chip Amps 23 18th July 2011 04:20 AM
Capacitor coupling question... rtate Solid State 9 2nd August 2009 08:28 PM
coupling capacitor value reading ccschua Parts 3 31st May 2009 01:51 PM
Need 33uF coupling capacitor eehobby Parts 2 3rd September 2003 02:53 AM
Pls Help... Capacitor Mounting JojoD818 Solid State 3 2nd April 2003 07:10 PM


New To Site? Need Help?

All times are GMT. The time now is 06:26 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2