World-Designs-Forum  

Go Back   World-Designs-Forum > WAD > WAD Problems
Register FAQ Members List Calendar Gallery Today's Posts Mark Forums Read

WAD Problems For questions and answers re older World Audio Design Projects

Reply
 
Thread Tools Display Modes
  #1  
Old 27th June 2020, 06:35 PM
hawkinsec hawkinsec is offline
Junior Member
 
Join Date: Jun 2020
Location: Peterborough, Cambridgesh
Posts: 28
Default Purpose of CF mod on Pre2?

I thought that I'd start a new thread rather than make this a continuation of my thread in the Coffee Bar.
I've had my Pre2, Phono2 and PS2 for just over a week now. I'm quite happy with the performance of the Phono and although I understand that there are improvements which can be made, there is no desperate need to do so. The Pre2 is a different matter as the sound quality took a dive when it was connected up. There is no hum and gain is not a problem, but all detail,bass and treble are absent. I did wonder if it was my imagination or I something, so I gave it a few days, but decided to have a play this morning.As soon as I got up, I connected the phono2 directly to the power amp. Everything sounded fine. Same story when DAC connected. I started to think about modding the Pre as suggest elsewhere , but on re-reading comments on my own post and others, I get the impression that the purpose of the CF mod is to get rid of the transformers and the tendency to hum. Would this be a pointless mod in my case?
__________________
Eddie
Reply With Quote
  #2  
Old 27th June 2020, 07:42 PM
bob orbell bob orbell is offline
Senior Member
 
Join Date: Nov 2009
Location: kettering northants.
Posts: 2,727
Default Re: Purpose of CF mod on Pre2?

No, it would restore the sound to very good, the pre II is rubbish, of course, the CF has no gain at all, but what it does have is current gain and for the likes of a White CF this would have a very good PSRR, why dont you also consider the CF that Matthew does, he should sell you just the PCB and components if you ask, another alternative is John Broski's Aikido CF from GLASSWARE, I use one as dose Bikerhifinut, fantastic. what ever route you take, you will also have to mod the PSU, no worries there, we can advise. Bob
Reply With Quote
  #3  
Old 27th June 2020, 08:54 PM
hawkinsec hawkinsec is offline
Junior Member
 
Join Date: Jun 2020
Location: Peterborough, Cambridgesh
Posts: 28
Default Re: Purpose of CF mod on Pre2?

Thank you, Bob. I'm sure that mine must be more grim than the norm. I'm even debating whether or not to get my Cambridge Audio A300 out of the loft to serve as a preamp.How would I get in touch with Matthew?
__________________
Eddie
Reply With Quote
  #4  
Old 27th June 2020, 10:41 PM
John Caswell John Caswell is offline
Super Moderator
 
Join Date: Dec 2005
Location: Wokingham, Berkshire
Posts: 1,780
Default Re: Purpose of CF mod on Pre2?

Bob wrote,
"the pre II is rubbish" pray explain

John
Reply With Quote
  #5  
Old 27th June 2020, 11:33 PM
hawkinsec hawkinsec is offline
Junior Member
 
Join Date: Jun 2020
Location: Peterborough, Cambridgesh
Posts: 28
Default Re: Purpose of CF mod on Pre2?

John. Are the symptoms I describe possibly due to some failure (component or construction) of the preamp? I'm quite willing (and eager) to investigate.
__________________
Eddie
Reply With Quote
  #6  
Old 28th June 2020, 06:38 AM
bob orbell bob orbell is offline
Senior Member
 
Join Date: Nov 2009
Location: kettering northants.
Posts: 2,727
Default Re: Purpose of CF mod on Pre2?

Quote:
Originally Posted by John Caswell View Post
Bob wrote,
"the pre II is rubbish" pray explain

John
John, the very first products I had from WAD were, KAT6550, Phono II, PSU II and Pre II, the KAT was built first , second the Phono and then the PSU , last I built the Pre, previously I was using Musical Fidelity kit on substituting the MF Pre for the Pre II, the sound was thin, bass was very poor and there was hum, I tried different valves, capacitors etc but nothing made this thing sound any good, on returning the MF made everything sound good again, I joined the forum and found N Gibbons thread on conversion to CF, and I am not alone with my thoughts on this piece of junk, I have stayed with CF to the present day. Bob
Reply With Quote
  #7  
Old 28th June 2020, 06:43 AM
bob orbell bob orbell is offline
Senior Member
 
Join Date: Nov 2009
Location: kettering northants.
Posts: 2,727
Thumbs up Re: Purpose of CF mod on Pre2?

Quote:
Originally Posted by hawkinsec View Post
Thank you, Bob. I'm sure that mine must be more grim than the norm. I'm even debating whether or not to get my Cambridge Audio A300 out of the loft to serve as a preamp.How would I get in touch with Matthew?
Matthew is the owner of WD and the forum, a very nice chap indeed, go to the bottom of the page on the right and click CONTACT US or visit WORLD-DESIGNS, leave an email or give Matthew a ring, he likes a natter . Bob
Reply With Quote
  #8  
Old 28th June 2020, 09:41 AM
pre65's Avatar
pre65 pre65 is offline
Senior Member
 
Join Date: Jan 2006
Location: Ashen- Essex/Suffolk bord
Posts: 4,538
Default Re: Purpose of CF mod on Pre2?

Quote:
Originally Posted by bob orbell View Post
John, the very first products I had from WAD were, KAT6550, Phono II, PSU II and Pre II, the KAT was built first , second the Phono and then the PSU , last I built the Pre, previously I was using Musical Fidelity kit on substituting the MF Pre for the Pre II, the sound was thin, bass was very poor and there was hum, I tried different valves, capacitors etc but nothing made this thing sound any good, on returning the MF made everything sound good again, I joined the forum and found N Gibbons thread on conversion to CF, and I am not alone with my thoughts on this piece of junk, I have stayed with CF to the present day. Bob
Bob, I wish you would stop this fixation on rubbishing things that YOU do not like. An honest opinion is one thing, but there are ways to express things without being (almost) offensive.

You had similar experiences (from memory) with a Garrard 401 some time ago, and we all know what a good bit of kit that can be.

So, it's not wrong to say that you don't like something, but just be careful how you say it.


*
__________________
Philip.

Everything in this post is my honest opinion based on what i thought I knew at that very moment in time.
Reply With Quote
  #9  
Old 28th June 2020, 10:35 AM
Greg.'s Avatar
Greg. Greg. is offline
WD Archivist
 
Join Date: Dec 2005
Location: Bristol, UK
Posts: 3,582
Default Re: Purpose of CF mod on Pre2?

In my experience, the Pre 2 was a competent performer sounding very similar to the Pre 3. I did not find the sound of Pre 2 thin or bass light. There were just two problems with it. The amount of gain was too much (fixable) for some systems and it was sensitive to placement in close proximity to other components which brought other transformers close resulting in hum. Keep those units, such as the Pre 2 and a power amp away from each other (suggested distance was 1 metre) and it performed very adequately. For many, me included, it was not practical to distance components, so an alternative had to be found. Initially I converted mine to a passive pre (at the time, WAD supplied a passive version) which got rid of both the hum and the gain. It sacrificed the drive and sparkle the Pre 2 had. Converting then to cathode follower Pre 2, brought back the drive and sparkle but without any gain. It was for many, a great solution.

Regarding Eddie’s original post, I suggest there is something amiss with the Pre 2 or how it is integrated with the rest of the system. It shouldn’t sound as Eddie has described. Eddie, please remind us what power amp you are using.
Reply With Quote
  #10  
Old 28th June 2020, 10:37 AM
John Caswell John Caswell is offline
Super Moderator
 
Join Date: Dec 2005
Location: Wokingham, Berkshire
Posts: 1,780
Default Re: Purpose of CF mod on Pre2?

Thanks Phil for beating me to the draw.
Lately there seems to be a drift towards slagging stuff off you personally do not like in somewhat rude terms, and the language is becoming ripe to whit Mr Orbells "Oh ****" heading.
If you cannot say things in sensible English don't say it at all.
I do not like censorship per se but if you cannot adhere to common sense and the rules .......
Although people seem to think the moderators are not watching - we are, so be prepared for the consequences.

John
Reply With Quote
Reply


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
Forum Jump


All times are GMT +1. The time now is 10:33 AM.


Powered by vBulletin® Version 3.7.3
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright World Designs