Concordant Excelsior Capacitor Upgrade

[audiojoy]

A superb preamp to this day. To my ears in my set up, the concordant/dynavector Hx bettered the naim 552 and 300.

So I thought about upgrading the caps first.

Every one goes on about the alps blue pot, but whats in those expensive Lebens and Lavardins and sonneter amps??? ALps Blue pots. BY far the most musical if not the most transparent, although in most systems it is more than adequate in my opinion.


The valve anode LCR smoothing caps have copies made by ASR so they were changed first. Made the sound slightly more dynamic, transparent and slightly more refined overall.

Then chnaged the 4 heater caps in the power supply to elna cerafine. Superb detail and claity and bass definition with refinement in great abundance. But the music was not making sense. Replaced the old cans and the magic returned halfway all be it with a return of the coarser sound. However to get the musicality fully back i managed to find LCR 100uf 500v caps so i used two in paralel and replaced the other ASR with the original. This brought the magic right back and if anything it was somewhat more involving and musical.

There are no labels on them and my meter states the capacitance is over 10000uf each. There are cg Mallory ones on my second concordant but it's power supply is identicle except for having half the number of capacitors for both supplies. However the two concordants almost sounded identicle in their respective unmodded versions.

SO I guess I better get NOS mallory CG for the heater supplies and see if that makes an improvement, especially in terms of 'roughness' to the sound. I dare not touch anything else, not even the wiring as Mr Dunlop really did listen and choose every component carefully. He understood what musicality was all about all those years ago. His absence and talent has been greatly missed.

Why are the heater dc smoothing caps making such a difference.

 

[LesW]

I liked the comments about the Alps pot as I was taken to task for using one in my headphone amp.
Agreed, it's not the most transparent but it sure delivers the tunes and let's face it, that's the goal.

The reason why the heater components have such effect is that the supply is half-wave rectified.
I used to haggle with Doug over this arguing that a custom transformer wouldn't be out of the
budget - all to no avail. He was a lovely bloke but stubborn as a pot mule.

To this day, I've fitted many a new transformer/rectifier system to these during upgrades I've
carried out - the improvement is very worth while.

Hope that helps and that you continue to enjoy for many years, Les

 

[audiojoy]

HI Les thanks for your reply.

It would have been fascinating meeting Doug.

Can you enlighten me more about the mod.

Yes as you said only two diodes are present in the dc heater circuit.

I am anxious about any changes to Dougs work, but if you felt that the main musical strengths were not affected in anyway whatsoever I might be interested in your mod.

Remember I have two concordant excelsiors and the enjoyment factor was so readily obvious with the heater supply cap changes. Getting the musicality side right is such a fine line. I fear any disturbance to the original circuit could never live up to the original sound, but perhaps thats my neurotic side coming through here. If Doug felt half wave recrification was the way to go then I am inclined (with all due respect to yourself) to believe that was not for cost cutting reasons. How much more could a couple of extra diodes have cost??

Sorry for sounding not totally sure about your mod but I am fascinated by the potential of this amplifier and your input.

Rest of system Tannoy Canterbury SE, naim hiline and powerline cabling. Naim NAC5 and yes it does work beautifully in my set up with the naim amps and the non naim amps. Densen 440xs cd player . Linn armageddon dynavector

 

[audiojoy]

I have had a chance to play around with the electrolytics.

The power supply caps need to be original LCR's to keep the same sound signature, only the large cap on the pre circuit can be substituted for the ARS equivalent. The latter does not work on the power supply smoothing position, it just slows the music down, no matter how much burn in. I have already burnt my fingers once with the elna cerafine in the heater power supply filter section. LCR's are the only way it seems to keep that same special sound.

AND YES that slight distorsion I was hearing has now completely gone on the modified version but remains on the unmodified one, along with improved dynamics and better tone. I am awaiting LCR smoothing caps from the USA exact NOS versions, to repalce the original heater ones and expect gains again.

 

[S-Man]

I also agree about Alps Blue.
I use a Panasonic in my main preamp and it has a slightly clearer sound whuist keeping all the musicality - unfortunately they stopped making them quite some time ago.

WRT caps, I generally find audio caps are not great sounding. Silmics tend to sound mushy, Muse tends to be bright and 'hifi', Panasonic for audio - bright. Stick with the industrial versions for a more 'normal' sound.

 

[Harry1212]

I also agree about Alps Blue.
I use a Panasonic in my main preamp and it has a slightly clearer sound whuist keeping all the musicality - unfortunately they stopped making them quite some time ago.

WRT caps, I generally find audio caps are not great sounding. Silmics tend to sound mushy, Muse tends to be bright and 'hifi', Panasonic for audio - bright. Stick with the industrial versions for a more 'normal' sound.

spot on

 

[Rana]

I have Doug's hand written circuit diagrams. If only I can remember where I put them...

 

[audiojoy]

Rana that would be great if you had copies of them, for repair purposes and ideas on capacitors and values he may have tried.

Please note ASR or ampmed are not exact copies of LCR capacitors as they do not sound the same. I have NOS LCR and they do sound the same but with slightly more clarity and refinenement. SO age cannot be blamed for the difference in sound.

 

[audiojoy]

UPDATE

The blue pot on its own as a passive is wonderfully musical when played directly through the dynavector hx1.2, yes a little lacking in transparency and inner detail. BUT in the concordant the transparency and detail is not lacking at all. So the alps blue pot may on its own apparently have inherent flaws but when part of a circuit it transforms into all that is needed for a high end musical sounding pot. Thats why they are used in amps costing as much as 5K



Secondly those blasted heater filter capacitors. I have now played around with LCR's, BHC, Mallory's Nichicon muse, elna cerafine, M Lytics and aerovox but by a country mile the most musical and enjoyable capacitor i could find in my box was one i cannot even remember buying. Its called a Marantz Nichicon with gold plated tags. I believe it is a combination of building blocks from Nichicons. Absolutely superb. The music flows swings and jives and thats all i care for. My foot taps and i get the groove. Even from what initally sounded like a mundane unknwon jazz quartet from the 50's, the music becomes enjoyable and dramatic....quick paced. Quite shocked to be honest to be able to beat Mr Dunlop. Mind you his 20 year old mallories were a close second and those expensive Marantz caps are probably of more recent invention.

Another unusal observation.... i have never heard a system so consistent in sound despite what interconnect you use. I used Naim Hi line, VDH the second and audio note ANv and could not tell the difference. That is a first for me because usually I am very easily capable of hearing differences betweeen the cables. I certainly could when it came to the capacitor changes!!!!

 

[Dan K]

I've got an Exhilarant... does your pre sit in a wooden box? I've been trying mine with and without the metal case and I have to say I think it is better without it.

Also...I found the TKD Pot to be better than the blue

 

[Rana]

@Audiojoy - I'll have a rummage through the attic
@Dan - in my system at that time (Concordant Quad II into Lowther Acoustas - I think that's what they were called) taking the metal enclosure off made a massive difference, so much so that my next order to Doug was for a wood cased Excelsior.