Building my own valve amp
 

"Nick Gorham" wrote in message
...
Trevor Wilson wrote:


What the OP needs to do is listen to those who are experienced with real
*buildable* circuits and follow the advice he likes the sound of best -
he's got to start somewhere and damn near every 'normal' PP amp on the
planet owes summat to the early Mullard designs (AFAIK) so why struggle
against it??


**Why trust what people say? Some people are seriously deluded. How is
Max to know if the people he is speaking to know anything at all? MUCH
better for him to listen to a product, BEFORE plonking down the cash.


Because the OP asked about BUILDING a amplifier, given you find this
mythical dealer that lets you geard some commercial amps, what then, ask
the maker for the winding schedule for their TX's

**How will he know what to build, unless he can listen to it? Valve amps
mostly sound different to each other. Their sound is largely differentiated
by the topolgy, the output transformers and the valves used. Without a good
listen to the amps, it is a total crap shoot. MUCH better to listen to
several amps and make a choice from those.



(Different with SETs of course, but I'd recommend a SET as a start amp
for a number of reasons!)


**SETs are for idiots.

"Why trust what people say? Some people are seriously deluded."

**Want me to explain to you why SET amps are for idiots? I'm quite happy to
explain in exquisite detail, that any technical person can understand.
You'll need to explain it to Iain though. He's not too bright in things
technical.

In any case, performing a blind test between a SET amp and pretty much
anything else is a most sobering experience.

Trevor Wilson

Building my own valve amp
 

**SETs are for idiots.

Trevor Wilson- Hide quoted text -

I can't believe that someone who has enough intelligence to read and
write can come up with such bull****.

Building my own valve amp
 

"Andy Evans" wrote in message
oups.com...
**SETs are for idiots.

Trevor Wilson- Hide quoted text -

I can't believe that someone who has enough intelligence to read and
write can come up with such bull****.

**Really? Please provide your explanation justifying the purchase of a SET
amplifier. In your explanation, please refer to the advantages of the design
(over a similar push pull one) and how those alleged advantages impact on
the sound quality.

Trevor Wilson

Building my own valve amp
 

Please provide your explanation justifying the purchase of a SET
amplifier. In your explanation, please refer to the advantages of the design (over a similar push pull one) and how those alleged advantages impact on the sound quality.
Trevor Wilson

I think the phrase you are looking for is "May I ask you..."

Anyway, moving on. You've made the assumption that I purchased a SET
amp, so you're already on the wrong track here.

I have indeed built several PP amps and recently built a 300b SET
which I like a lot. All the amps I build are all-DHT, so they are
pretty different already from the norm, though not from each other.
I'm fairly familiar with the sound of various DHTs through building
several amps and preamps using them, so I hope I can give some idea of
how the SET differs from the PP amps. The timbre of acoustic
instruments is probably the main characteristic where the SET excels.
Bass is better than I expected, treble is detailed. I'd say there was
a softer attack on the leading edge of notes, but not that I would
worry too much about, and this is compensated for by the timbre
referred to above. It's a very musical amp, and that is important. I
could go on and give some definitions of musical, but frankly I'd be
happier to leave that to the common sense of musical listeners. I
can't be totally accurate about an A-B comparison since the SET used
46 and 300b and the PP amps used 26 and 2a3s. But I can use my
existing knowledge of the sound of these particular DHTs to have a
reasonable idea of what to attribute to the SET topology. I could
probably give you a more detailed comparative account in a year or so
by which time I expect to build about 4 more SETs. I still like PP -
it has a clean and clear presentation which remains attractive. But
I'm sufficiantly impressed by what I'm hearing out of my SET to
continue the experiment.

Building my own valve amp
 

"Andy Evans" wrote in message
ps.com...
Please provide your explanation justifying the purchase of a SET
amplifier. In your explanation, please refer to the advantages of the
design (over a similar push pull one) and how those alleged advantages
impact on the sound quality.
Trevor Wilson

I think the phrase you are looking for is "May I ask you..."

Anyway, moving on. You've made the assumption that I purchased a SET
amp, so you're already on the wrong track here.

**I made no such assumption. I asked you to justify the purchase of one. You
defended the purchase/building of SET amps.


I have indeed built several PP amps and recently built a 300b SET
which I like a lot. All the amps I build are all-DHT, so they are
pretty different already from the norm, though not from each other.
I'm fairly familiar with the sound of various DHTs through building
several amps and preamps using them, so I hope I can give some idea of
how the SET differs from the PP amps. The timbre of acoustic
instruments is probably the main characteristic where the SET excels.
Bass is better than I expected, treble is detailed. I'd say there was
a softer attack on the leading edge of notes, but not that I would
worry too much about, and this is compensated for by the timbre
referred to above. It's a very musical amp, and that is important. I
could go on and give some definitions of musical, but frankly I'd be
happier to leave that to the common sense of musical listeners. I
can't be totally accurate about an A-B comparison since the SET used
46 and 300b and the PP amps used 26 and 2a3s. But I can use my
existing knowledge of the sound of these particular DHTs to have a
reasonable idea of what to attribute to the SET topology. I could
probably give you a more detailed comparative account in a year or so
by which time I expect to build about 4 more SETs. I still like PP -
it has a clean and clear presentation which remains attractive. But
I'm sufficiantly impressed by what I'm hearing out of my SET to
continue the experiment.

**Which doesn't answer my question. Try again.

Trevor Wilson

Building my own valve amp
 

**Far and away, the biggest variable with a valve amp is the output
transformer.

That's an exaggeration. I wouldn't say the difference was much, if at
all, bigger than that between a pentode EL34 output tube and a 300b
DHT.

I can't speak for amorphous core or 50% nickel variants, which may be
more dissimilar. But these are relatively rare and I doubt that you
were referring to them. Correct me if I'm wrong.

Building my own valve amp
 

The trouble with listening to a *range* of valve amps is that, after the
first 2 or 3 dozen, they all start to sound the same....- Hide quoted text -


I wouldn't say a pentode feedback amp with indirectly heated valves
sounds anywhere near the same as an all DHT amp with zero global
negative feedback.

Building my own valve amp
 

"Andy Evans" wrote in message
oups.com...
**Far and away, the biggest variable with a valve amp is the output
transformer.

That's an exaggeration. I wouldn't say the difference was much, if at
all, bigger than that between a pentode EL34 output tube and a 300b
DHT.

I can't speak for amorphous core or 50% nickel variants, which may be
more dissimilar. But these are relatively rare and I doubt that you
were referring to them. Correct me if I'm wrong.

**You are wrong. Quality transformers are typically constructed using grain
oriented silicon steel, with many interleaves. Crappy transformers (such as
those often supplied with cheap, crappy Chinese valve amps) use regular
steel and few, if any interleaves. The best I've ever seen used 15
interleaves.

Trevor Wilson

Trevor Wilson

Building my own valve amp
 

Trevor Wilson wrote:

"Andy Evans" wrote in message
oups.com...

**Far and away, the biggest variable with a valve amp is the output
transformer.

That's an exaggeration. I wouldn't say the difference was much, if at
all, bigger than that between a pentode EL34 output tube and a 300b
DHT.

I can't speak for amorphous core or 50% nickel variants, which may be
more dissimilar. But these are relatively rare and I doubt that you
were referring to them. Correct me if I'm wrong.


**You are wrong. Quality transformers are typically constructed using grain
oriented silicon steel, with many interleaves. Crappy transformers (such as
those often supplied with cheap, crappy Chinese valve amps) use regular
steel and few, if any interleaves. The best I've ever seen used 15
interleaves.

Trevor Wilson

Trevor Wilson



Trevor, why do you insist on answering a question that hasn't been asked?

The OP asked about building his own amp, so I still don't see how
listening to commercial amps has any bearing. For all we know, he has
done that.

The question wasn't even "what amp should I build?"

--
Nick

Building my own valve amp
 

In article , Nick Gorham
wrote:

Trevor, why do you insist on answering a question that hasn't been asked?

The OP asked about building his own amp, so I still don't see how
listening to commercial amps has any bearing. For all we know, he has
done that.

This prompts the question in my mind: What use does the OP intend to make
of the amp, and what does he expect/wish to do?

The question wasn't even "what amp should I build?"

I am not clear if the OP just wants to see if he can build a working valve
(power) amp and then put it on the shelf as a 'trophy', like some people
build plastic kit models. Or if the plan is to make use of it to play
music, with the idea being that it will sound 'different' to a purchased
transistor amp. Which is it? Or does he have a different reason?

The answers to these questions might affect the advice given. :-)

So far, I'd think the best advice has both been to read up on the topic
*and* to listen to amps. But beyond that I think we'd need more info from
the OP as to his aims/reasons.

Slainte,

Jim

--
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