Valve amp questions/advice

ellison

Novice Member
I recently purchased a second hand (though unopened) Vincent SV-236MK hybrid amp.I've always had integrated amps and so am not that familiar with amps that contain valves.While im pretty sure that the valves will last a fair amount of time,just how would I know when they are deteriorating?.Does the sound change dramatically ,or is the wear and tear on the valves very gradual?.Also would it be wise to purchase spare valves now ,in case of price increase or are the prices pretty much stable?.Any other info/tips/advice much appreciated
tia
ellison
 

Mark.Yudkin

Distinguished Member
I recently purchased a second hand (though unopened) Vincent SV-236MK hybrid amp.I've always had integrated amps and so am not that familiar with amps that contain valves.While im pretty sure that the valves will last a fair amount of time,just how would I know when they are deteriorating?.Does the sound change dramatically ,or is the wear and tear on the valves very gradual?.Also would it be wise to purchase spare valves now ,in case of price increase or are the prices pretty much stable?.Any other info/tips/advice much appreciated
Valves are like incandescent light bulbs - they work until they blow, and failure follows an exponential distribution. In simple terms, how long a valve will last is essentially independent of how long it has already lasted, it may last 2 decades or 2 minutes, failure is catastrophic, not gradual, and you have no way of predicting failure. All that can be given is an average lifetime (from a large sample), and it is not independent of the manufacturer.

The Vincent SV-236MK uses the popular 12AX7 valves, and continued availablity at a consistent price seems likely to me. But whether you feel it would be wise to purchase spare valves is like your investing in stock - it's up to you to make your decision as to how you think prices and availability will develop - I am not a valve market analyst.
 

nwgarratt

Member
My Dad's amp has just had a valve replaced. It was arcing and turned it straight off to prevent any more damage. It is wise to have spares just in case and there were spares for the other valves but not this one. Another one was ordered on ebay but decided to get one from the US as it was the same Russian make as the old one. It was £13 delivered and it is up and working again.

I used to have a valve amp myself and still prefer the sound from them but valves are tricky and have settled for just solid state amp for ease.
 

Ianfromnotts

Well-known Member
small valves like the ECC83/12ax7 usually last for years, far longer than the big ones. The most sought after versions were made years ago (40+) and are much sought after, £120 each is quite possible for some ECC83/12ax7 and matched pairs/triples even more, I saw one pair at US$500 the other day. These will continue to increase in price no doubt.

New tubes will probably start at about £7 each.

Used valves that have tested and confirmed within spec is another option, prices vary widely according to make and model.

If you have worries about your tubes you could take them out and find a valve specialist to test them but if it is a new amp I reckon the valves should be good for a fair few years to come, 4-5 at least. Personally I have never had a small pre amp valve fail.
 

ellison

Novice Member
Thanks everyone for replies.I expect the valves to last a while as the unit is in pristine condition,and was in a sealed box.The remote also in a sealed bag.I wasnt sure whether the valve would gradually deteriorate or just fail ,so thanks Mark for the info.Is there any well known or recommended dealer to buy valves from?.
tia
ellison
 

Mark.Yudkin

Distinguished Member
Thanks everyone for replies.I expect the valves to last a while as the unit is in pristine condition,and was in a sealed box.The remote also in a sealed bag.I wasnt sure whether the valve would gradually deteriorate or just fail ,so thanks Mark for the info.Is there any well known or recommended dealer to buy valves from?.
Vincent is a reputable German manufacturer of quality tube amps and is well.known and respected here in CH. Their home page is Vincent-Tac - High-End tube, phono & power amplifiers - Vincent-TAC.

They or their local distributor will happily and competently service your SV-236MK using quality replacement parts if such should be needed.
 

ellison

Novice Member
Thanks everyone for links.I didn't like the valve sound for about a week (guess I'm used to solid state?) and to get a sound that I'm liking and appreciating more and more ,I actually used the Vincents tone controls ...anathema to some but heaven to me :)
 

ellison

Novice Member
Well I usually have the amp on when I'm home as the TV goes through it too so its on for a good 5 hours a day.There,s no standby on the Vincent and its just power on.I found the music reproduction the best I've heard from any amp,but the vocal reproduction sounded "veiled" to my old ears.However a bit of treble has rectified that ,and I'm now acknowledging that it is the best sounding amp I've owned ...so far.
 

nwgarratt

Member
I have been trying to remember the valve amp I had, It took looking through past forum posts to find it. It was a Audio Innovation Series 400. I used it with a Technics deck and B&W 601 S2 which I still use today.

audioinnovationsclassic.jpg
 

alexs2

Well-known Member
I've had quite a few valve amps,and still own a few.

The small signal tubes generally last for tens of thousands of hours,whereas power tubes have lives measured in thousands of hours.

The problem is that deterioration over that time can be quite subtle,and not easily noticed until you replace the tubes.
Most of us don't have access to,or don't want to bother with tube testers,which will give a clear indication of when one is pretty much finished,but replacing some of the modern tubes with NOS(new old stock) equivalents can produce surprising results.

Some of the newer chinese tubes are very good indeed(like the TJs)but some from before that are truly awful,but cheap and widely used.

I've used Chelmer Valve Co.for many years,and found them to have some of the best stocks of old tubes anywhere.

CVC
 

nwgarratt

Member
Valve amps are still my favourite over solid state but over time they were not practical for me.

They were best for me with vinyl and even CD but I tried it with a PC and a DAB/FM radio. It was not suitable for use for short period of times. I also don't have room for two amps/speakers. The room also got quite hot as well. A person could tell they were on when coming into the room.

Six months ago, I turned down a Word Audio Design amp built my Dad just because I had no room. Now he has passed away, I wished I had it, although I am not sure how not having a phono stage would work. He had the WAD Phono II and PSU II setup, One psu controlling two phono stages for two amps.

The Audio Innovations had an integrated phono stage.
 

alexs2

Well-known Member
Valve amps are still my favourite over solid state but over time they were not practical for me.

They were best for me with vinyl and even CD but I tried it with a PC and a DAB/FM radio. It was not suitable for use for short period of times. I also don't have room for two amps/speakers. The room also got quite hot as well. A person could tell they were on when coming into the room.

Six months ago, I turned down a Word Audio Design amp built my Dad just because I had no room. Now he has passed away, I wished I had it, although I am not sure how not having a phono stage would work. He had the WAD Phono II and PSU II setup, One psu controlling two phono stages for two amps.

The Audio Innovations had an integrated phono stage.

Definitely my overall favourites for sound quality although the sound of triodes as compared to ultralinear or pentode etc etc can be very different.

My first was an Earmax headphone amp,followed by Tube Technology Genesis monoblocs which I had wired in triode mode,and along the way since,

Quad IIs(which I still have)
World Audio 300B mono amps(working nicely)
Cary 300B SEi which is my headphone amp.

Love the glow of tubes....
 

nwgarratt

Member
This was my Dad's Triode amp.


The world audio design amp is underneath (not in video). It looks like it is the KIT6550 amp.

He also made the 300 Monoblocs in the past.
 

ellison

Novice Member
Thats a nice looking setup ,and sounds good too :).
You mentioned the heat from those valve amps.I am quite suprised how cool the vincent is.In fact it doesn't get half as hot as the XTZ A 100 D3 that I also have.I did expect much more heat to be generated from the vincent (although it does have exceptional cooling fins).Ive run the vincent as loud as is pleasurable in my front room ,and the casing is just luke warm.I really expected it to be as hot as the XTZ at least ,but it isnt.Though i guess its only a partial valve setup so i guess that explains it :rolleyes:
ellison
 

alexs2

Well-known Member
Thats a nice looking setup ,and sounds good too :).
You mentioned the heat from those valve amps.I am quite suprised how cool the vincent is.In fact it doesn't get half as hot as the XTZ A 100 D3 that I also have.I did expect much more heat to be generated from the vincent (although it does have exceptional cooling fins).Ive run the vincent as loud as is pleasurable in my front room ,and the casing is just luke warm.I really expected it to be as hot as the XTZ at least ,but it isnt.Though i guess its only a partial valve setup so i guess that explains it :rolleyes:
ellison

Small tubes like the 12AX7 don't really produce a lot of heat....


If you want heat,you need one of these....

833A - Wikipedia, the free encyclopedia

And yes,some companies do make hifi amps based around old transmitter tubes,admittedly most being 211 or 845 tubes,and not that monster above.
 

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