Yarland valve amps - any comments??. Plus Melbourne HiFi show.

[hal55]

I'm used to the hifi press generally giving, with a few exceptions, Chinese amps a bad rap. As a result I tend to automaticlly assume that an unreviewed amp from China must be pretty poor even though I use Chinese electronics in my system (Little Dot Mk3 preamp, Lite Dac60, Jungson JA99C power amp). I'm very happy with each of these components.
In the current HifI News there is a review, very very positive, of the latst Yarland amp, an FV 34b. I love valves and would like to get a valve amp again having had two of the beasties in the past and loving them. Anyone have actual ears on experience with Yarland and can comment? I heard some lovely valve stuff at the Melbourne HiFi show a few months ago and it has rekindled an urge to get a valve amp again. The fact that it has 3 inputs and remote control is also a huge advantage over my lovely but one input LD Mk3.

Anyone else attend the Melbourne show and if so what did you think of it - personally I had a great time and am desperately hoping for another in 2012.

Hal55

[Michael Jones]

We have a review of the Yarland FV34c (http://audioenz.co.nz/2010/yarland_fv34c.shtml) on AudioEnz.

[911man]

What I can tell you is this, we sell them in our store, and for the money I would like to know where anyone could find something better. They sound incredibly warm, and fat, but they are also not a sluggish sound like a few I have heard.
I honestly can't find anything negative about the F34. It even looks like it comes from a factory that care about how there amplifiers look.
If you are thinking about getting one just have a demo and you'll be pretty impressed.
Remember what they cost when you audition one!

[kaka]

The Wgtn Audio club had a club member demo the Yarland Pro88 (it did have better than stock valves in it) and it was extrememly enjoyable. Steve (of Soul to Sole, the importer) was down another night and played the Sugden monoblocks ($20k ish), Sugden integrated and a Yarland 34B with Treasure valves.

I preferred the Yarland. Great sound for such an astonishing low price. The big Sugdens coupled with efficient Living Voice speakers overdid the bass in that room, though I know that combo has been enjoyed at various dealer demos.

On the basis of what I have heard, the Yarlands are seriously good sonic and monetary value.

[hal55]

Interesting, and very impressive that such a low priced item could compete so well. Treasure valves seem to quote their valve as a 6CA7, it's pricey but seems to be worth it from the comments I've seen. Anyone know the NZ/Aust price for this amp?

Hal55

[Owen Young]

6CA7 is an EL34 equivalent valve.

[kaka]

Interesting, and very impressive that such a low priced item could compete so well. Treasure valves seem to quote their valve as a 6CA7, it's pricey but seems to be worth it from the comments I've seen. Anyone know the NZ/Aust price for this amp?

Hal55

The speakers, cables and sources weren't low priced! Living Voice, Kondo, late model Sugden CD player and VPI turntable (with $5k cart). We suffer from room effects too.

It would be a case of hear for yourself, but you will probably be impressed for the price

[hal55]

I'm a long way from a valve expert, but my limited knowledge is that a 6CA7 is a beefed up American EL34 type that, if done to specificaton, is about 50% beefier than the EL34. Sort of halfway between EL34 and KT88 specs.
As I undersand it, that's the theory anyway.

Hal55

[jasper]

Hi Hal55

The Yarland FV-34B retails in NZ for $1499, which includes our 15% GST which would not be applicable to Australia.

I have just finished running in the Shuguang Treasure 6CA7-Z valves on one and there is a definite improvement over the stock valves. I am now stocking these new and they retail (per pair) here for $265.00.

Doing this provides a bit of an upgrade path for this amp and also swapping the stock 12AX7 for a nice NOS one or even a new Sovtek 5751 seems to work very nicely with this model.
Interestingly I tried some NOS Raytheon 5670 in place of the two stock chinese 6N3 tubes and preferred the stock tubes. Had more bite and excitement I thought.

Shipping this model to Australia is approximately NZ$230.00

Steve

[Owen Young]

I'm a long way from a valve expert, but my limited knowledge is that a 6CA7 is a beefed up American EL34 type that, if done to specificaton, is about 50% beefier than the EL34. Sort of halfway between EL34 and KT88 specs.
As I undersand it, that's the theory anyway.

Hal55
Hmmm, that's an interesting point hal...I've always understood that the 6CA7 was the American identical version of the EL34. However it's not uncommon for Chinese valves to be labelled one thing & be structurally based on another valve adapted into a different envelope, eg. early Chinese KT88 was really more like a 6550.

The EL34 was a Mullard-Philips design from the early 50s. Looking at the datasheets again, I'm pretty sure that the EL34 *IS* a 6CA7. However, as said, modern versions of valves often boast *improved* specifications & sometimes this is true. The downside, however, is that it may not then be a good idea to swap in a NOS valve, as the maximum ratings could be less than the newer valve for which the amp was designed.

[MosfetMainac]

As far as I'm aware the 6CA7 is identical to the EL34.

There tends to be some confusion caused by the glass envelope used by American manufacturers which is much larger, often these tubes are called "Fat Boys", whereas the Euro/GB tubes tend to be slimmer in design, Siemens and AWA tubes being the slimmest
Their electrical characteristics are the same however.

In general 6CA7= EL34 = 6p27s, and similar(different pin outs) to EL37 and KT77

You may be thinking of the 6L6 vs the 6L6GC, the GC can endure much higher plate voltages and output is increased?

[pocoloco]

The only other value tube amp I could think of would be those Miniwatt amps but they only output about 3.5w so really only good for very sensitive speakers.

Did a bit of research when I was still looking for an amp and the 34c and 35a (4th generation only) are both auto-biasing for those who are just getting into tubes..or don't like getting their hands dirty :p

[Owen Young]

Did a bit of research when I was still looking for an amp and the 34c and 35a (4th generation only) are both auto-biasing for those who are just getting into tubes..or don't like getting their hands dirty :pThat may be a useful consideration, poco.
It's been a while since I owned an EL34 amp (Radford STA25) but looking at the Yarland 34B specs with 40wpc from 2xEL34 in pentode PP, I'd guess that it would be Fixed Bias... ie. user manually set bias for ea tube. (I might be completely wrong here, so perhaps someone with info could comment.)

[davyboy9]

Consider one of the Norh SE amps either the 9 or the 18.
Just a thought.

[pocoloco]

That may be a useful consideration, poco.
It's been a while since I owned an EL34 amp (Radford STA25) but looking at the Yarland 34B specs with 40wpc from 2xEL34 in pentode PP, I'd guess that it would be Fixed Bias... ie. user manually set bias for ea tube. (I might be completely wrong here, so perhaps someone with info could comment.)

The Yarland website specifies what type of bias control the amplifier has. Seems that only their low watt amplifiers are auto-configuring unfortunately :(.

Self-support bias = auto configuring / Regular bias = manual configuring

[hal55]

Looks as though I was wrong in stating that a 6CA7 is a beefed up EL34, but from hunting around the net it seems the construction is different for each, ie
"Technically speaking, the old production, US made "fat bottle" 6CA7s are beam tetrodes in that they have only two grid windings. Beam forming plates take the place of g3. They look somewhat like healthy 6L6GCs and the beam forming plates are plainly visible if you you look close. AFAIK, only GE and Sylvania/Philips ECG made these although they were rebranded by others. They're very rugged and apparently have a following in the guitar world. There are current versions being mfgd by Sovtek and others and these too are beam tetrodes.

EL34s are true pentodes in that they have three grid windings and no beam forming plates. They're almost always in tall, smaller diameter bottles compared to 6CA7s. True pentode EL34s have been mfgd just about everywhere but the US."

KT88s are beam tetrodes so that seems to be where I got the impression that they were similar. Curiously, I knew a manufacturer of valve amps many, many years ago who was excited that KT77s "were going back into production". It now seems this valve is just the same as EL34/6CA7 so I'll cheerfully give up and admit that everything I thought I knew is likely wrong.

Currently looking at my surplus hifi stuff that can be sold and fund a nice little valve amp, likely the Yarland.

Cheers,

Hal55

[jasper]

There is one biasing pot on each side of the 34B that biases the two output valves on the respective sides. This necessitates that the valves are pretty close in measurement to each other and this has generally been the case.
When using the Treasure 6CA7-Z tubes Yarland recommend a slightly higher bias of 35mA as opposed the the 32mA used with the stock EL34 valves.

[Owen Young]

Well hal, this is useful discussion for those interested in learning more about valves & power tubes. And you are largely correct, the EL34 history is not straightforward, as the EL34 was a breakthrough Philips-Mullard patented design with low cost among other things & other manufs were keen to introduce their own innovations.

Here is a pic of valve construction showing the the 5-electrode Pentode compared Beam Power Tube/Beam Tetrode/Kinkless Tetrode design with its ‘beam forming plates’.

7721

You can see the 3rd Grid of the pentode (the ‘suppression grid’) was deleted & a pair of beam forming plates introduced to ‘focus’ the electrons from the cathode toward the outer plate (anode). The suppressor grid was originally there to catch stray electrons coming off the plate. The beam power tube improved efficiency (of tetrodes), esp at low power levels.

The orig Philips-Mullard EL34/6CA7 was made also by Philips-Amperex, Telefunken, Siemens, GE, Sylvania, RCA/Radiotron, Toshiba, Matsushita…

In the 70s a more rugged version 6CA7 STR (special test requirement) was introduced (by Sylvania, GE) specifically for US guitar amp makers (who run their tubes hard) & had a short ‘fat’ 6L6GC type envelope.

The KT77 – a new one to me. Introduced by MOV (British GE) in 1959. looked like an EL34 but was a beam tetrode inside & more rugged, like the 6CA7 STR.

Phew, enough already!
(Most of the above gleaned from Eric Barbour’s VTV article on EL34s.)

[hal55]

Amen, it's enough to make your head spin, which I thought it was doing from lacquering a plinth for a SP10 today and being affected by the fumes. It was probably from trying to get my head around all this valve construction stuff!


Hal55