A question about valve amps

[nuff]

Good morning everyone!
I'm after a bit of advice.

I've been thinking for a while of selling off my 2 amps and settling on a valve amp. I just love the look of them glowing at night.

My problem I think would be my speakers. Bowers & Wilkins 683. Am I correct in thinking that they would be no good for a valve setup? I don't really want to sell them as they were a present from the wife a few years ago when I was into home theatre.

I'm playing a lot of vinyl lately and as i live in a terrace i never really crank it up too high. I have a firebottle plus in the system too, Would i use this along side?

If anyone could advice me if this is a good or bad idea I'd appreciate it.

In terms of cash I was thinking around the £500 - £600 mark.
Nathan.

[anthonyTD]

Hi Nathan,
Did you have any info regarding graphs on impedance, versus frequency whith the speakers ?
There is a lot of Diss-information regarding the suitability of valve amps with certain speakers,[push-pull, and single ended] its not all about SPL,and sensitivity, speakers that have very complicated cross-overs can be an issue with both Solid state and valves, check what info you have on your speakers and post it here, that will be a good starting point. :)
A...

[Firebottle]

Hi Nathan,

I don't think you have a problem at all. The 683's are reasonably efficient at 89dB so something along the lines of an EL84 push pull should suit well.

Buy an integrated with 2-3 inputs and just plug the Firebottle in one for your vinyl, sorted.

Cheers,
Alan

[Reffc]

You wont get much for that budget unfortunately Nathan and certainly nothing that would be up to the rest of your system. Your speakers are described as a nominal 8 Ohm load (meaningless term unless one can see where it is at 8 Ohms!) and dips to 3 Ohms. Most speakers have their minimum impedance in the bass registers (not always though; it depends on drive units used and crossover design) and if yours are 3 Ohms between their lower roll off and say 100 Hz, then they'd probably operate OK with a valve amp with 4 Ohm tappings. As Anthony has already said though, you need really to have more information such as the graphs of frequency and impedance but also the phase angles, especially at the most demanding loads.

At your budget you would be better advised sticking with SS as you can buy a heck of a lot better for the money. Most budget valve amps use poor quality output transformers and so-so power supplies (again, a generalisation because decent output transformers with low output impedance and wide bandwidth cost money) and in general, unless you get lucky, you wont find much decent in valve terms much under £1000 these days even on the used market. You could look for some vintage amps but again, at that budget they'd be likely to require servicing. Even something a really good Leak Stereo 20 fetches £700 + these days.

You'd be down an alley that many have trodden, forming opinions on valve amps having access only to budget and most likely of Chinese origin. Better saving the pennies and investing in a good used better quality valve amp. The exception might be to look for something like a good used WAD KT88 amp as those are sometimes available within budget but you'll need a pre to match it, so that has to be factored in. There are one or two budget Chinese amps that may be ok like the Yaquin MC100B which has gained a following amongst those on a budget.

My advice to people looking to buy valve amps on the cheap is, generally speaking,"don't" as it can be a waste of money.

[struth]

if you do go for something like a yaqin that are well enough made and do sound good then you have to fettle the mains for them as they almost all 220v so a bucking tx or similar is a must or trouble will happen sooner or later. i had one with a bu king tx in a separate box and it worked flawlessly. you may well find an el34 amp second hand for that money. maybe a wad one that should be good but as said without the full response graphs it can be a matter of try and see. i might add that some amps also need manually biased so youd need to either kniw someone or be prepared to use a multimeter and adjust it yourself. its not difficult but can be daunting the first time. you also have to cansider placement due to heat and any little fingers if you have family

[Joe]

The only bit of advice I'd throw in is, before you decide to go the valve route, make sure you have access to someone competent to service/repair a valve amp, unless you're confident with DIY or prepared to learn. This applies especially if you are buying secondhand.

[DSJR]

I should add that in my experience of the 680's (limited I admit) that the the B&W 680 series' speakers are almost certainly not getting the best from your system either, but you'd have to do some more listening away from the chain dealers to confirm this. remember, no way must the 680 series compare with the CM's which come above (too loose and hollow vs. a carrot stuck up their virtual backside - you decide :)). Of the mid period B&W ranges, I was rather fond of the CDM7 and a pair of these might be within you budget on the used market. I have to say that the Naim SBL is very much a 'sleeper' on the used market and if re-set up carefully, can sound really good OUTSIDE of a Naim system. I saw a pair the other day for £400 in black, and they had the later bass units too... You never know, but the passive crossovers may also be upgradeable, as Naim would never have allowed the passive ones normally to come close to the active version... I've been tempted myself, would you believe :eek:

For me, good valve amps able to drive a pretty wide speaker load tend to start at around £2k (happy to be proved wrong here). Maybe a WAD kit on the used market, but these are more fun projects I think at the lower end of their range. This is why Glenn Croft went over to valve driven MOS-FETs in his power amps and he claims the performance is rather better than his older all-valve designs.

[nuff]

Good morning!

Thanks to all who has replied, a very interesting read from everyone.
I think I may just bite the bullet and buy a valve amp for the money I have. I think trial & error is only going to sort this out. I know some of you might be thinking Crazy fool! But you never know I might be very happy.

I have been looking at YAQIN MC-100B on the bay (Grant I’m sure you had 1 of these didn't you?)
I have noticed there is 3 different types, GB, SV, & BK. What’s the difference?
http://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2047675.m570.l1313.TR0.TRC0.H0.XYAQIN+MC-100B.TRS0&_nkw=YAQIN+MC-100B&_sacat=0
If someone has any other recommendations within my budget could you let me know please?

A big thank you again to all who have taken time to help me.
Nathan.

[Reffc]

The power supply on those will saturate at UK mains voltages and you will be over-loading the amp. It will run higher HT voltages and driver valve filament voltages than designed to cope with, increasing distortion, shortening valve life and shortening power supply life. They are 115 or 230V so you ought really to use them with a step down transformer or 230V power supply...If you dont, there is a reasonable chance you'll have a failure within the first few years. Plenty of documented evidence on the net to support this. Anthony I'm sure can elaborate more accurately than myself on this.

[struth]

yep, mine was a 220v and mine had a 24v bucking transformer in line reducing it to 220 in. if you were getting a 230v one the i would suggest youd be better probably using a mains regenerator. that outputs a steady 230v.power inspired is the one i have and is very good.
the 100b is a decent amp as long as the mains is sortred. i would be inclined to wait a little though Nathan as some nice valve amps crop up hear and other sites at decent prices. remember youll have inport duties etc if you bring it in from china which knock up the price plus youll want to put better valves in and b4 you know it your spending more than you think you were gonna.
not wanting to put you off just letting you know the potential costs and pitfalls:)

[walpurgis]

The voltage matching on much Chinese equipment is not ideal for UK mains. But some makes will specify proper UK spec mains transformers. I believe MingDa (Meixing) and Raphaelite (Sinovt) do. They are among the better quality Chinese makes.

[Macca]

I'm familiar with the B&W 683 and I'm sceptical that they would work well with a low powered valve amp. If you are going to try it buy second-hand so that if it doesn't work you don't take a hit.

[anthonyTD]

A lot of good advice for you to chew on, as for chinese valve amps, especialy The Yaqin,[a very good platform for the money] i have a lot of experience with those as i used to offer serious modifications for them when they first apeared on the Bay etc. Unfortunetly, most do suffer power related issues,[most of the ones for sale outside of the UK are designed to run on 220v] and on testing the mains voltage needed for all voltages on the secondary side of the power supply to be correct, i found that most only required around 207v, which when you realise our UK mains voltage can vary between 238v and up to 255v, its no wonder people were soon reporting spectacular failiers with many of them! Therefore, A step down transformer which will drop off around 30v is a must to run them safely on our voltage.
There are a good few decent valve amps for sale on the second hand market, but do some homework before you splash out on something you may later regret!
A...

[Audio Al]

Nathan

Can you budget stretch to this :- http://www.ebay.co.uk/itm/Audio-Innovations-Series-500-valve-amplifier-Upgraded-and-serviced-Spare-tubes-/171840235033?pt=LH_DefaultDomain_3&hash=item280279e619

Has a built in phono stage and lots of upgrade already done

I have one of these and its very nice , also has the ability to run 4 / 8 and 16 ohm speakers ( see the binding posts on the rear of the amp )

If you were closer you could borrow my one for a week , but Bristol 2 London 4 times would be a bind

:)

[Audio Al]

Also at some point :scratch: AOS is supposed to be auctioning off a John Wood valve amp thats been checked over by our very own Antony TD

[struth]

both are excellent options...

[Spectral Morn]

Nathan

Can you budget stretch to this :- http://www.ebay.co.uk/itm/Audio-Innovations-Series-500-valve-amplifier-Upgraded-and-serviced-Spare-tubes-/171840235033?pt=LH_DefaultDomain_3&hash=item280279e619

Has a built in phono stage and lots of upgrade already done

I have one of these and its very nice , also has the ability to run 4 / 8 and 16 ohm speakers ( see the binding posts on the rear of the amp )

If you were closer you could borrow my one for a week , but Bristol 2 London 4 times would be a bind

:)

Not suitable. In my experience - I own one - it doesn't have the ability to drive those speakers the op owns.


Regards Neil

[nuff]

Another lot of very interesting and useful advice from you all.
I'm now starting to think your all right in saying hold on. To be honest I haven't the funds as of yet so I think I may hold off for a while. I think my choices of cheap valve amps are very limited due to my speakers.
I didn't really want to sell them or spend anymore on the amp. Audio Al your very kind to offer yours to me to borrow but as you said it's a hell of a trip up to you.
I think I'll start saving and when the time comes make a decision on speakers.

[cloth-ears]

Hi Nathan, before investing in a valve amp I think it is important to look at the pros and cons.

If you have reached a crossroads in the pursuit of HiFi excellence there are quite a few options to consider before going valve. Valve amps ask more questions than they answer
For a start power, power comes at a price; a big price. Any quality amplifier under a grand is unlikely to produce more than 25 watts or so. Therefore speaker choice is critical. Valve amplifiers have a high output impedance and although there are some speakers that work well with high output impedance these are in the minority. Finding a speaker that both matches this criteria and your musical choice is critical as any mistake will prove costly

Also valve amplifiers are not “buy and forget”; they require regular servicing in order to keep them at their best. Ancillary components such as capacitors have a service life. This service life is much reduced with heat, an unfortunate by-product of valve equipment.

Valve amplifiers produce distortion in an order of magnitude far higher than transistors. Although this distortion occurs in an area that is usually inoffensive it is still there. At clipping point they are very forgiving and are thus the weapon of choice for a fair few guitarists. In a domestic environment however this is more often than not of little or no consequence

Finding the right valve amplifier speaker combination though difficult is often rewarding to some. Depending on your musical preferences then valves may well be the answer. This is a choice that only you can make. Personally, before making that decision I would explore other avenues; but that is only my opinion.

Good luck and I really do hope you get what you are looking for

[Box13]

Good morning everyone!
I'm after a bit of advice.

I've been thinking for a while of selling off my 2 amps and settling on a valve amp. I just love the look of them glowing at night.

My problem I think would be my speakers. Bowers & Wilkins 683. Am I correct in thinking that they would be no good for a valve setup? I don't really want to sell them as they were a present from the wife a few years ago when I was into home theatre.

I'm playing a lot of vinyl lately and as i live in a terrace i never really crank it up too high. I have a firebottle plus in the system too, Would i use this along side?

If anyone could advice me if this is a good or bad idea I'd appreciate it.

In terms of cash I was thinking around the £500 - £600 mark.
Nathan.

A very cost effective way to try the sound would be by buying one of these little beauties first.

Little Bear BK P5 6J1 x2 HiFi tube valve buffer Preamp Preamplifier amplifier

[Gordon Steadman]

If you could stretch the budget a little

http://www.ebay.co.uk/itm/leak-stereo-20-very-good-example-serviced-and-working-well-/252013314448?pt=LH_DefaultDomain_3&hash=item3aad2a019
(http://www.ebay.co.uk/itm/leak-stereo-20-very-good-example-serviced-and-working-well-/252013314448?pt=LH_DefaultDomain_3&hash=item3aad2a0190)

You will need a pre-amp of course, I use a passive. My Leak drives just about anything to adequate if not head banging levels. I repaired a pair of B&W 603/2s recently and it had no problem with them at all. Playing Bach organ music was satisfyingly weighty.

[cloth-ears]

I forgot to mention that if you are looking for a good speaker to match valve amplifiers I would ask for advice from Paul, AKA “Reffc”. Although we do not always agree with each other I must say that his knowledge in this area is extensive and as such would recommend any advice he could give without hesitation