changing the amplifier

[biszibosz]

Hello Everyone,
Firs post - first issue.

I would like to get yor opinion on the following: changing the Arcam amp for valve amp.

For starters, i know little about the valve amplifiers. I know the power has to be sufficient to power up
speakers, and i know that it needs to have a phono stage for hoking up TT, or additional phono pre-amp
has to be introduced (for TT that is) , but other than that - its all a mystery to me...

Currently the system looks like this:

main source - Pro Ject RPM5 turntable (LINN cables, Ortofon cart.)
cd - Arcam Alpha 7 (14 year old beast)
amp - Arcam Diva A70
speakers - System Audio 1530 (3-way floorstanders)
(Also, i hooked up my plazma to the amp to watch movies with a nice touch of quality sound)


Now, obviously im tight on the budget.

I could possibly drop off CD to strip it down to main source only, however i dont plan to get a receiver
soon, so TV woudl be probably hooked up as well. I know, it sounds like a heresy(or not?) but i cant
think of anything else atm. Hence the amp would need to have at least 2 RCA inputs.

Also, i would not mind changing the SA speakers to other ones, even smaller bookshelves on stands
just to lower down the power requirement for the valve amp.

So essentially i could change the whole lot leaving the pro-ject TT.

I listen to ambient and modern classical mostly, a bit of electronic music and field recordings,
various experimental stuff etc, so what i need is warm sound, no unnecessary "punches", no "disco
bass", no "bounce" needed.

Because of the budget i would opt for second hand equipment.

Kronos gave me already a bit of info, David has Dared amp for sale for a reasonable price.

I have also found this:
http://www.hifiandaudio.com/p88i.htm

but obviously i cant go to listen to it. Im pretty much limited to "buy on recoomendation" as Kronos
and Cloneys are the ony ones in the country anyway (im based in Athy).

Ive also found an old ad from here now being sold in CLoneys for a very nice price: Antique Sound lab AQ 2004 pre + 2 x Av20 mono power amps - but i have no clue whether they would be ok for my system.

I would appreciate your thoughts/opinions on the above.

No rush as well, i have plenty of time, so i can sit down and wait for a good occasion on ebay or something
but i would prefer at least to have something recomended not to buy stuff blindfolded...

Thanks in advance,
Marcin.

[Ivor]

I think your first issue is...... will a valve amp drive the SA speakers?

I understand that they are quite easy to drive but if anybody here has used a valve amp with SA floorstanders they might post up their expierience?

[woody]

hi marcin..i used to own these and i can confirm that they sound very good indeed..to your list of amps to try i would recommend affordable valve co and icon audio..david shaw is particularly helpful..for a first valve amp i would recommend a 30 to 40w push pull,el34's,6550's,6l6's and kt88's would be a good starting point without going too hard on budget..decent power as well,some of the other members would be pretty knowledgable on vintage gear(im not)and may be able to give you some advice there....single ended may be a bit too demanding and expensive for the moment,unless you really get the valve bug...cheers..frank.

[woody]

didnt see that,its a fair point,i have found that floorstanders work very well with valves,but a lot of drivers can cause problems,can cause a lack of control,like the drivers are not timing properly,do the sa's have very small drivers? may alleviate that if they are...frank. ps..i wouldnt recommend small speakers,floorstanders are generally easier to drive,higher sensitivity is very desirable when dealing with low to medium power valve amps...

[Fran]

Woodys advice is good - and I think cloney sell sa speakers so a call to them might help. They might even be able to do a demo for you - as might kronos.

A few members here have sa 1530 so might know what they need to power them.

Fran

[biszibosz]

HI All,

Thanks for the answer.

Ive found this for the SA :

technical specifications

power handling 130 Watt
frequency range 40-35.000 Hz (+/- 1.5 dB)
impedance 4-8 Ohm

so im guessing any valve amp with 8ohm output would be ok ?

Now, i would love to get your opinions on the one i have shown you - even though i wont be able to listen to it ite the cheapest one...
http://www.hifiandaudio.com/p88i.htm


SE88i valve amplifier Specifications.
- Output power : 2 x 10W
- Frequency response : 20Hz ~ 20KHz ± 1.5dB
- Input sensitivity : 550mV
- Total harmonic distortion : <1% (440Hz)
- Output impedance : 4 ohms, 8 ohms
- Input impedance : 50 K ohms
- Vacuum tubes : KT88 x 2, 12AU7 x 2, 12AX7 x 1
- Voltage : 110V or 230V
- Power consumption : 70W
- Signal to noise ratio : 90dB

does it mean its only 2x10W so it wouldnt drive the columns as should ?

and this - i think its my favourite:
http://www.hifiandaudio.com/e34i.htm
EL34 valve amplifier Specifications.
- Output power : 2 x 40W
- Frequency response : 20Hz ~ 30KHz ±1.5dB
- Input sensitivity : 650 ~ 750mV
- Total harmonic distortion : < 1% (440Hz)
- Output impedance : 4 ohms, 8 ohms
- Input impedance : 50 K ohms

8ohms, 2x40W - sounds about right ?

Thanks

[Fran]

Id be looking at the el34 amp first. There's a couple of reasons:

1. More power which will help.

2. El34 in push pull will be very clean sound so while 40w is maybe a bit generous for a pair of el34 you will still have 30 clean watts.

3. I'd be willing to bet that its a clone of a dynaco st 70 - well regarded amp.

4. El34 are a nice sounding valve.

Fran

[Adrian]

Interesting link biszibosz,

I would agree with Fran there on the EL34 above the SE10 unit.

Unless you have very efficient speakers 10W is a bit on the low side. Hence 40W EL34 will do nicely for most speakers at modest volume levels etc.

The site looks interesting, and it is good that they post a photo of the internal wiring to see what is going on inside the amplifier. It gives one an idea of how it is put together, quality of workmanship etc etc.

As you say the downside is that you cannot go and have a look, listen when buying off the www. However for those prices they are very very cheap.

However if it was my choice, I would tend towards the P88i, 50W KT88 unit. It looks very good and the KT88 is a good valve. For £535 you are getting a valve amplifier at a very cheap price. Not too sure if you will get it through customs with out paying vat, or does £535 include UK VAT? If it does include UK vat then you might not have to pay vat here, otherwise you would be paying vat twice. Might need to check that out, anybody else know???

Other costs are delivery charges, the problem with valves amps is that they are a bit on the heavy side, so will cost a few quid to lug it your door.

I like the option of paying with Paypal.

I reckon either the EL34 or P88i Kt88 unit will work fine with the SA1530's.

Adrian

[biszibosz]

Hi,

Thanks for the input;

Upon additional searches ive found a website showing close-ups of the mentioned valve amp,
what more - they even show how they package the thing for shipment !

here:
http://www.separo.com.cn/en/products/pr ... 6&MaxID=22

Can anyone judge these by the workmanship and wiring ? It looks like a neat job...

It also seems they manufacture these in China and the UK website is an english reseller.
I dont know whether chinese valve amps are trustworthy ? I've heard of Xindak, but thats
about it for chinese manufacturer's...

Thanks.

[Fran]

It looks very nicely made - and point to point which makes it much easier for repairs down the line should they be needed. Make sure they give you a schematic no matter which one you buy. Chances are you will end up changing out the valves for real 6SN7s - everybody ends up doing this I think. The only thing you really can't see is the size and quality of the power and output transformers. That is where the big bucks are in a valve amp, and while they might be AOK, at the same time they might be mediocre and you end up with muddy bass. The best thing to do is google around a bit and see how other have got on with it. If there aren;t any reviews/opinions out there, I wouldn't buy. Also, beware of reviews on fora - theres always a big flavour of the month (FOTM) thing.

If it ships from within the EU, you will pay VAT in the country of origin (eg 17% in the UK) and no duties/vat payable here. If its coming from outside the EU you might or might not get away with it. Chances of getting away with it are getting less and less all the time. Shipping is gonna hurt because of the weight of it - and the packing looks good.

I would imagine that the EL34 looks very similar in its pics with similar level of construction. I doj't know about the extra $$ for the KT88 over the EL34. In my situation both would be more than I needed so its not an issue. Might be different for the SAs though.

I would say have a look at what Woody said up above about affordable valve company in the UK. I gather they get these amps made in china but then do a final tweak and tune up on them in the UK. What this really means is that you have access to someone who speaks good english. Chances are though, that if something blew up in it, you could always get a replacement part easily.

Fran