Not the easiest speaker to drive (they need a bit of power) but I fancy
giving valves a try. Anyone have a recommendations where to start. The
system is 'budget' and well chosen, with a DPA Little Bit 3 DAC as a main
source and currently running a Cambridge Audio A1MkIII SE transistor amp.

Will

Will Reeve wrote:
Not the easiest speaker to drive (they need a bit of power) but I fancy
giving valves a try. Anyone have a recommendations where to start. The
system is 'budget' and well chosen, with a DPA Little Bit 3 DAC as a main
source and currently running a Cambridge Audio A1MkIII SE transistor amp.

Will



I don't know the speakers, so I am not sure just how much "a bit" of
power is.

One choice would be WAD's ket84, which is a cracking little amp.

http://www.worldaudiodesign.com/cata...hp?cPath=26_31

Onother (though not DIY) would be one of the el34 amps Keith got from
ebay, I am sure he will post some details, or if you look at some of the
older posting you should see details of them,

--
Nick

What I do is build the lot up from scratch. Choose a circuit, choose a box, get
the parts and start building. If you are anywhere near Kensington, London, drop
in and you can leave with whatever you want - built, part built, kits, chassis,
valves - whatever. I have a lot of surplus stuff right now, so it won't be
expensive.
I started by repairing existing amps, and still have some Leaks lying about.
When you start running out of room in those chassis, it pays to build bigger
because you really need some big parts - chokes, polypropylene caps, that kind
of thing. I've gone over to 19" subracks. I like it because it's modular,
there's plenty of bits around, it's nice shiny aluminium, and turned on its end
it looks surprisingly like a Nagra! There are all sorts of possibilities with
subracks. Otherwise get a chunky top plate in thick aluminium and put a wood
frame around it (various skirting boards fit) or use a 19" case, something like
2U. I bought a few from Maplins that have perforated tops, which are ideal for
fixing stuff to.
Choice of circuit? How about Allen Wright's stuff. He has circuits on his site
- good modern designs. Well worth a build.
http://www.vacuumstate.com/schematics.htm Andy

=== Andy Evans ===
Visit our Website:- http://www.artsandmedia.com
Audio, music and health pages and interesting links.

"Nick Gorham" wrote in message
...
Will Reeve wrote:
Not the easiest speaker to drive (they need a bit of power) but I fancy
giving valves a try. Anyone have a recommendations where to start. The
system is 'budget' and well chosen, with a DPA Little Bit 3 DAC as a main
source and currently running a Cambridge Audio A1MkIII SE transistor amp.

Will

I don't know the speakers, so I am not sure just how much "a bit" of power
is.

One choice would be WAD's ket84, which is a cracking little amp.

http://www.worldaudiodesign.com/cata...hp?cPath=26_31

Onother (though not DIY) would be one of the el34 amps Keith got from
ebay, I am sure he will post some details, or if you look at some of the
older posting you should see details of them,



Indeed I will - see the 'cheapychinky' pix on my Show N Tell page:

http://www.apah69.dsl.pipex.com/keith_g/show/show.htm

.....for a selection of snaps of the rather good little Chinese amps that are
on eBay for £213 + P&P atm. (Search 'Dynavox'). Loopy VFM and these amps
will drive any Wharfedale, I'm sure. (Not too 'diy' though!)

For DIY, as Nick says, the World Audio kits are to be very highly
recommended, but the prices are starting to look a little high compared with
the recent influx of Chinese amps. A WAD kit would arguably give you a
'better' amp, but the Chinese amps are looking to be really quite good
indeed for the price. Cheaper than a WAD kit would be to have a go at a
'build from scratch' from a kit of parts - contact Phil at Bluebell Audio:

http://www.bluebellaudio.com/

who would, I'm sure, be pleased to discuss your requirements. He would be
able to supply everyting you need as well as the circuits and maybe a pic or
two of a similar project. Talk to him nicely and I believe he'll also punch
out the chassis for you....???

"Will Reeve" wrote in message
...
Not the easiest speaker to drive (they need a bit of power) but I fancy
giving valves a try.

**Why?

Do you have a desire to buy an amp which:
* Delivers less power.
* Consumes more power.
* Begins to wear out, from the first instant it is switched on.
* Has a declining base of ready availability of spare parts.
* Delivers a poorer frequency response.
* Delivers higher levels of all types of distortion.
* Possesses a poorer phase response.
Than a similarly priced SS amp?

Anyone have a recommendations where to start. The
system is 'budget' and well chosen, with a DPA Little Bit 3 DAC as a main
source and currently running a Cambridge Audio A1MkIII SE transistor amp.

**A nice little Rotel RA02 will do nicely. It'll likely last a long time,
too.


--
Trevor Wilson
www.rageaudio.com.au

Not the easiest speaker to drive (they need a bit of power) but I fancy
giving valves a try.

**Why?

I think he's saying that he wants to see if he likes the sound of valves. I'm
sure he could answer this more fully himself if he would like to.

=== Andy Evans ===
Visit our Website:- http://www.artsandmedia.com
Audio, music and health pages and interesting links.

On Sun, 07 Nov 2004 17:28:55 +0000, Will Reeve wrote:

Not the easiest speaker to drive (they need a bit of power) but I fancy
giving valves a try. Anyone have a recommendations where to start. The
system is 'budget' and well chosen, with a DPA Little Bit 3 DAC as a main
source and currently running a Cambridge Audio A1MkIII SE transistor amp.


Well, your current amp is, what, 30W per channel? Are you happy with that
sort of power?

Unless you want to try valves just for the fun of it then I would
recommend sticking with ss if your speakers are a difficult load. To get
something of comparable power for a reasonable price you are going to be
looking at a p-p design using something like 6L6 or EL34 valves (as
tetrode or pentode connection - forget triode connection here). Don't
forget that the bulk of your cash has to go on output transformers. Don't
get cheap iron. Pay attention to the power supply design too, it is just
as important as the output stage.

If you are just curious of course you could try something like
single-ended 6L6s with a load of about 4k or 5k. They sound nice wired as
triodes (but only about 1.1W output), and if you keep the HT down to 270V
it makes it easy to reconfigure them as tetrodes to get more output (about
6.5W). The low HT also means that you don't need to worry about where you
get them from as even the cheap russian versions can handle this ok. There
are better output valves but the 6L6 is cheap, reliable and easy to get.
It is also pretty efficient so the cost of your power supply can be quite
reasonable.

You never know - you may even get to like this stuff & join the ranks of
those of us who are always on the look out for very efficient speakers!

--
Mick
(no M$ software on here... :-) )
Web: http://www.nascom.info

Trevor Wilson wrote:
"Will Reeve" wrote in message
...
Not the easiest speaker to drive (they need a bit of power) but I
fancy giving valves a try.

**Why?

Do you have a desire to buy an amp which:
* Delivers less power.

A small worry, but I don't play very loud and I believe when you push them
they "soft" clip so reducing the chance of tweeter frying?

* Consumes more power.

I presume you mean less efficient, it's winter I will turn the heating down
:-)

* Begins to wear out, from the first instant it is switched on.

I won't mention that I sometimes listen to vinyl then :-)

* Has a declining base of ready availability of spare parts.

I hope to use valves still manufactured and resistors / caps are readily
available (nothing exotic) from Farnell.

* Delivers a poorer frequency response.

Unlikely poorer than the speakers, these are small boxes!

* Delivers higher levels of all types of distortion.

Isn't that why the sound different and appeal to many people?

* Possesses a poorer phase response.
Than a similarly priced SS amp?

Anyone have a recommendations where to start. The
system is 'budget' and well chosen, with a DPA Little Bit 3 DAC as a
main source and currently running a Cambridge Audio A1MkIII SE
transistor amp.

**A nice little Rotel RA02 will do nicely. It'll likely last a long
time, too.

Hi guys, thanks for the replies. I've been lurking on the group for a few
months and always enjoy the analogue/digital and valves/ss arguments :-) I
hope you don't mind but I will answer/comment on everyone's replies in one
post.

The wharefdale diamond 'speaker is a mid eighties very small shelf speaker
which
doesn't do 'low' and is a little inefficient. I love them. I believe they
were around 100quid when first available! I've just got a set of the 'super'
version which have real wood and veneered cabinets! They live in a
cluttered office and it's a timber framed house so not ideal acoustics.

I'm too young to have witnessed valves the first time around and fancy
giving
them a go now for a Christmas project!

I love the look of the glowing valves; I do solid state
for a living and fancy something a bit different.

I like to compare the whole Hi-Fi world to my other passion...cars. I think
the valve amp is a bit like a classic car, some can be cheap and bloody good
fun (I have a TR7 V8 ragtop) other expensive and more reliable. I
certainly wouldn't want to do a long trip in a cheap one or use it as my
everyday reliable transport but as a bit of fun and something different for
the weekend, why not?

On a more practical note I have a friend who can laser cut/drill highly
polished stainless steel, however I am having difficulty it finding where I
can get wooded side panels made (I intend to use the stainless for the top
and bottom plates). So if anyone can make the wood I can get the plates and
do a swap! I was thinking a nice varnished hardwood and polished stainless
would look very nice!

My budget is 150quid max (excluding enclosure) and something easy to wire by
hand, not many valves, and warm sound to soften CD would be nice. Thanks for
the links I have found from previous replies much better than the ones I
generated with Google. I have a few evenings of surfing / reading to do! I
guess transformers from somewhere like sowter will be 100quid of that
budget?

Keep well all,


Will

My budget is 150quid max

That's fine. My current amp could be built for that. 2x Maplins output
transformers @ £30 = £60.
Four Maplins chokes at £7 = £28
Mains transformer, isolation toroid £20-ish
2x Heater transformer - CPC 06-06 20VA £5-ish, or one bigger for stereo amp.
ss diodes or Damper Diodes (tubes) run off 6.3v heaters (email me for details)
peanuts. Polypropylene caps for PSU (Maplins) - £15. Resistors and other caps
- peanuts.
Four Teflon coupling capacitors .1 £10 or less. That's about the budget. Still
leaves tubes, so I'd suggest something good and cheap. I'd use EH 7591 output
tubes, a 6J5GT (7193) first stage into a 12b4 concertina. Nothing too expensive
there. It would be worth going slightly over budget for this, since the sound
is truly excellent - very neutral and detailed. I can supply circuit. Andy

=== Andy Evans ===
Visit our Website:- http://www.artsandmedia.com
Audio, music and health pages and interesting links.

On Tue, 9 Nov 2004 13:07:00 -0000, "Will Reeve"
wrote:

I'm too young to have witnessed valves the first time around and fancy
giving
them a go now for a Christmas project!

I love the look of the glowing valves; I do solid state
for a living and fancy something a bit different.

I like to compare the whole Hi-Fi world to my other passion...cars. I think
the valve amp is a bit like a classic car, some can be cheap and bloody good
fun (I have a TR7 V8 ragtop) other expensive and more reliable. I
certainly wouldn't want to do a long trip in a cheap one or use it as my
everyday reliable transport but as a bit of fun and something different for
the weekend, why not?

On a more practical note I have a friend who can laser cut/drill highly
polished stainless steel, however I am having difficulty it finding where I
can get wooded side panels made (I intend to use the stainless for the top
and bottom plates). So if anyone can make the wood I can get the plates and
do a swap! I was thinking a nice varnished hardwood and polished stainless
would look very nice!

My budget is 150quid max (excluding enclosure) and something easy to wire by
hand, not many valves, and warm sound to soften CD would be nice. Thanks for
the links I have found from previous replies much better than the ones I
generated with Google. I have a few evenings of surfing / reading to do! I
guess transformers from somewhere like sowter will be 100quid of that
budget?

Correct, but OTOH the output transfomers are by far the most important
part of any valve amp. BTW, just one caveat if you 'do solid state for
a living' and fancy playing with valves - digging about inside valve
amps can get you *killed* very quickly! Do have proper respect for
large DC voltages with chunky amounts of current behind them, they'll
stop your heart in a heartbeat - so to speak.................
--

Stewart Pinkerton | Music is Art - Audio is Engineering