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  #1  
Old 30th January 2017, 09:19 PM
JohnG JohnG is offline
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Default Klp1

Hello
I am a new member to WDF and am feeling good about being able to access a community that enjoys the WAD projects.
I have been associated with WAD since the mid 90's, until about 2004, then after a series of house moves and other things, the HiFi remained in storage
until december 2016.
I have never built a project, these were done by the same valve engineer.
We are at present re-establishing our system, to how we remember it.
As well as going forward with a completion of partially finished projects.
We have also expressed the wish to upgrade some of the components to extract a little more in replay performance.
At present we have a KLP1, K5881 - MK1, Andy Groves design, solid state phono stage. ESL 57. A Goldring Lenco 75 overhaul and new plinth project began in January 2017.
As a initial upgrade I would like to find out if the KLP1 will benefit from improved components, and as it will also be a supporting pre amp for another power amp project that is 50% complete, I was informed it will need more gain.
I would appreciate any ideas on how to improve the KLP1 as well as add gain.

John
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  #2  
Old 30th January 2017, 09:43 PM
bob orbell bob orbell is offline
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Default Re: Klp1

Hi John, the KLP1 is a strange product, I think that I am correct that it has two valves, using only half of each valve, it is a cathode follower, John Caswell has the CD drawings, the heaters are AC , and it has a full wave voltage doubler, 100 volts from the transformer doubled to 200, I put one together last year from bits and I disposed of it for it was no good, you will not be able to increase the gain as it is only unity gain, a buffer. BOB
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  #3  
Old 30th January 2017, 11:11 PM
davebms davebms is offline
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Question Re: Klp1

hello all,,, (quote) disposed of it for it was no good,

that's a bit harsh !! I had an article on kpl1, it might have been in the old
WD forum,, the thoughts were that it was ok,, ,but the power
supply was not up to the job ,, does john need more gain ?

dave
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  #4  
Old 31st January 2017, 07:13 AM
JohnG JohnG is offline
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Default Re: Klp1

Thank you
I suspected there was a limit to the upgrade path, as the klp1 has not received much coverage on this subject.
I am happy to be open minded, and look at a new DIY line stage pre amp, utilising the Klp1 casing as a housing.
Which DIY model would be a affordable and improved build.
It will eventually, have a valve phono stage go through it, and be working with 845 push pull mono blocks optimised at 25 watts.

John
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  #5  
Old 31st January 2017, 10:00 AM
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pre65 pre65 is offline
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Default Re: Klp1

845 push pull monoblocks ?

That's ambitious.

Is it worth the complexity (and cost) for 25 watts ?

I'd like to hear a bit more about the parts you will use, particularly with regard to output transformers.
__________________
Philip.

Everything in this post is my honest opinion based on what i thought I knew at that very moment in time.
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  #6  
Old 31st January 2017, 11:02 AM
Richard Richard is offline
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Default Re: Klp1

Hi John and welcome.
Perhaps you can tell us the sensitivity of your power amps.
Many power amps these days are line sensitive (typically 300-500mV) and sources usually have enough voltage to drive them (typically 500-2000mV).
That leaves some power amps needing 1-2V in something of a minority.
Many preamps have become buffers/vol control/selectors rather than amps per se. Others like WAD Pre2/3 have good gain as designed but if (for the previous reasons) folk don't need the gain they convert them to unity buffers.
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  #7  
Old 7th February 2017, 01:23 PM
westiebj westiebj is offline
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Default Re: Klp1

Hi

I have recently built the Phono3 and PSU3 kits using an existing WAD KLPP1 case

Matthew at WD was very supportive and happy to provide kits minus the cases and assorted pieces of HW no longer required

I believe a similar result could be achieved using the KLP case ( I think its the same as KLPP1 ) and the WD Pre3 / PSU, although you would have to check the sizes of the Pre3 PCB

I am very happy with the result ... the Phono3 is still burning in but the sound is excellent, far better than my original KLPP1

I have attached some photos showing the layout plus a new perspex faceplate which I chose to match other kit I owned

Rgds
Attached Images
File Type: jpg IMG_1757mr.jpg (123.2 KB, 45 views)
File Type: jpg IMG_1759mr.jpg (118.5 KB, 36 views)
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  #8  
Old 7th February 2017, 01:23 PM
westiebj westiebj is offline
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Default Re: Klp1

Two more pics ..
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File Type: jpg IMG_1760mr.jpg (121.5 KB, 29 views)
File Type: jpg IMG_1765mr.jpg (74.4 KB, 29 views)
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  #9  
Old 7th February 2017, 01:42 PM
bikerhifinut bikerhifinut is offline
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Default Re: Klp1

That's nice!

now I know what i'd do if I was the OP.

I'd get a Phono3 kit sans case and the parts to make a preamp of choice, it looks possible to squeeze a pre3 in there or easily put a simpler circuit in alongside it.
Then I'd add an offboard PSU which gives the advantage of flexibility of PSU choice and complexity. And reduce or eliminate any danger of PSU noise and hum getting into the sensitive disc stage. The Phono 3S has the capability to be totally silent in terms of hum, it's only valve Hiss that I usually hear with mine.
Ah yes isn't that what i am considering to do with the prototype preamp case I obtained off Nigel a couple of years back............ thats based on the WD headphone amp case so there's an idea for those thinking of an "all in one".

At the risk of being pilloried by the die hards and forced to do penance, I have to make a big confession here. I often use a solid state preamp. it's a Rega Cursa3 which is a very transparent piece of kit, very like a passive with "drive" for long cable runs that I use. This as well as a Broskie Aikido cathode follower as I do not need gain for my power amps. Depends on my mood. But the rambling point i wish to make is don't discount silicon as those pesky op amps and transistor things can be made to work very well with valve power amps.
Again I am using at times a very good solid state disc stage that for me just works. I like to keep an open mind and don't disregard any technology out of hand and i think its good to compare old and new technology.
to Bob O, I will have to get a pair of those resistor values you mentioned as my phono3 although very sweet does seem to miss a bit of "mojo" and perhaps thats the synergy thats missing?

A.

Last edited by bikerhifinut; 7th February 2017 at 01:44 PM. Reason: explanation.
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  #10  
Old 7th February 2017, 02:33 PM
bob orbell bob orbell is offline
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Default Re: Klp1

Andy, I have loads here if you give me your address, I will post a couple. BOB
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