DIY 859 Tube Amp
Chris Fang
So far I have only acquired the output transformers. I cannot find a
chassis large enough to accommodate both output and input transformers
so I have opted to build the power supply in a separate box, with cables
carrying the HT and heater supplies to the amplification stages.
My questions are as follows:
Are there any real drawbacks to this arrangement apart form extra cable?
Does anyone have any addresses where I can obtain chassis from? The ones
I have in mind come from Triode Electronics in Chicago.
Christopher Fang
cs...@cam.ac.uk
University of Cambridge
Ashley Stevens
> I have decided to go ahead and build an EAR 859 tube amp from scratch.
Did your output transformers come with a circuit diagram? Tim Paravicini
told me that there are deliberate errors in the circuit in HFN&RR, to
prevent copying.
TDP is a nutter who thinks that everyone is out to copy his ideas you
see. The stuff about putting the circuit in the public domain was
nonsense. He wants to see if anyone will try to copy it. One the other
hand, maybe he's just covering up the mistakes he made!
Anyway, make sure you have the *correct* ciruit diagram, unless you
understand enough about the circuit to spot the errors for yourself!
I built mine from the kit.
Ashley
Tubesguy
also when deciding whether to build the amp. After doing so, I decided
not to. I have some parts, by the way, including PCC88 matched pairs (let
me guess, he meant ECC) and non-inductive ww cathode resistors(again,
foolishly in the values specified.)
RickLB
pretty decent amp of its kind and a very clever piece of design,
but I know kits are apt to be minus a part or two, also he
casually substitutes what to him are equivalents but not to
anyone who doesn't understand the amp well. BTW, PCC88 and ECC88
are, I believe, interchangeable, although in general E- and P-
valves aren't.
Yves C Vidal #93146
|> I have decided to go ahead and build an EAR 859 tube amp from scratch.
|> chassis large enough to accommodate both output and input transformers
|> so I have opted to build the power supply in a separate box, with cables
|> carrying the HT and heater supplies to the amplification stages.
|>
|> My questions are as follows:
|>
|> Are there any real drawbacks to this arrangement apart form extra cable?
|> Does anyone have any addresses where I can obtain chassis from? The ones
|> I have in mind come from Triode Electronics in Chicago.
|>
On the contrary. The fabulous JADIS JA200 are made in such a way. The Power
supply is on a totally different chassis for each monoblock amp.
Yves
Mike Glantz
of design"
True. Too bad Tim dP can't take credit for it (which he does). His
"enhanced triode mode operation" was described in RCA receiving tube
manuals (and earlier) as a way of driving pentodes. It wasn't called
anything special or exotic, just driving the screen grids with the
input signal.
People who lie (or are just plain stupid - is there another, kinder
explanation?) to enhance their own reputation can't be trusted to
design reliable products, and I, for one, will never buy one of his.
Doug Forbes
Tubesguy (tube...@aol.com) wrote:
: Glad to hear that someone else thinks that Tim is nuts. I spoke with him
It's too bad you decided not to build the amp, I've been listening to one
for about 9 months and really like it. I wound the outputs and thus
didn't have to rely on Tim's transformer winder (still don't think he's
shipping) and am using 6JE6's instead of PL509's. I ran some plate curves
and found the "Enhanced Mode" really refers to the fact that the tube
looks like a MOSFET not at all like a triode..
Doug Forbes
--
dfo...@netcom.com
Ashley Stevens
> It's too bad you decided not to build the amp, I've been listening to
> one for about 9 months and really like it. I wound the outputs and
> thus didn't have to rely on Tim's transformer winder (still don't
> think he's shipping) and am using 6JE6's instead of PL509's. I ran
> some plate curves and found the "Enhanced Mode" really refers to the
> fact that the tube looks like a MOSFET not at all like a triode..
I've been listening to an 859 for 3 months and it sounds great, but Tim
is still nuts. He also went bankrupt 5 months ago, which is why I'm
growing increasing worried that I am never going to get the chrome front
panel, gilt knobs, and chrome transformer covers for my kit, that I paid
for, and have been waiting for now for 4.5 months....
Ashley
Stephen Delft
re: DIY amp thread.
I have only recently plugged into this conf, and am obviously at
the tail end of a thread. However, I do make small batches of
amps for musicians, and I am most interested in the "enhanced mode"
// "screen-drive" aspect of this thread. Would you be very
kind, and fax or airmail me a copy of the schematic?
FAX ( int code for New Zealand) then 4 528 1437
Snail mail Box 40 559, Upper Hutt, New Zealand
Many thanks, Stephen Delft, Upper Hutt, New Zealand
---
* SPEED 1.00 [NR] * No?! Some people still read mail a packet at a time?!
Mike Glantz
aspect of this thread. Would you be very kind, and fax or airmail
me a copy of the schematic?"
In spite of Mr DeParavicini's probably honest claims to have
discovered this technique himself, you can find it in any copy of an
RCA receiving tube manual from the 1950s. If these aren't available
at a respectable library in Kiwiland, please let us know.
RickLB
still trading as Yoshino Ltd and still making 859 kits and built
amps, still actually supplying them that is - last time I was at
his works he had at least a dozen chassis with transformers on
waiting to go out. Anyone having trouble getting panels and bits
should just hassle him - he's a forgetful SOB sometimes.
Couple other points in this thread;
PCC88 and ECC88 are as far as I remember interchangeable, as it
happens - tho of course this is not generally true of Exxx and
Pxxx valves.
Enhanced mode triode in RCA tube manual eh? Tim probably does
know about that as he has most of those - I'll ask him <g>. Maybe
he's only the first to use it in audio or something. Anyway it's
a good way to get good reliability as most tubes like high anode
and low screen volts.
Any more ?s on 859s, email me - I can probably answer most of
'em.
Cheers all,
Richard.