"Phil North" wrote in message
...
Hi all,

I took a bit of a gamble and bought a valve phono stage off ebay recently.
Upon hearing it I thought the sound was great but lacking in bass but put
that partly down to the equipment I was using it with (home made speakers
that have lived in the loft for 10 years).

I took it round to Keiths on Tuesday and tried it on all his amps and it
was still bass light on his Dynavox and WAD amps but to my ears was
absolutely superb on the triode amp. This amp seemed to bring out the bass
and make the sort of sound I am searching for, something I could listen to
all day with any kind of music.


:-)

(Cheque's in the post, Phil.... ;-)



We did some comparisons with Keiths EAR phono stage and on the triode amp
I thought the Ming Da was better. On the other amps the EAR was best but
for me that was only due to the better bass and myself and Nigel thought
the EAR had too much bass at times.


Worth pointing out here that Shiny Nigel has the same EAR phono stage and
he's been in two minds about it since he got it. (Lasted nearly a fortnight
before it went tits-up - OK, fixed in an instant at the EAR manufactory some
10 minutes from here, I have to admit...!!)


This phono stage cost me 140 pounds plus 60 quid delivery from China, and
with a few tweaks to get some bass out (suggestions welcome) or the
cloning of Keiths triode amp may be the only one I ever buy.
I make no claims to it being hi-fi but as something to make my music
enjoyable I love it.



'Not hifi, but *enjoyable*'..??? (Now, there's a thought!! :-)


OK, in case anyone is interested, a bit more information:

The object of the exercise was to check Phil's suspicions that the Ming Da
phono stage was a bit 'bass light' and to compare it directly with my
EAR834P phono which has a rep for being a bit fat-arsed and is generally
despised by one here who shall remain nameless. (Won't they Nick? ;-). This
was using a Shure V15 V xMR into B&W DM2As which have got a good bass if
well fed, can be a bit woolly if not and the bass from the Shure can bend
iron bars, if needed..... :-)

Straight off, on material like Bjork and Pink Floyd (even the Beatles at one
stage) it was apparent that the bass was much lighter on the Ming Da.
Whether it was *too* light was another matter, however. The Ming Da
(beautifully constructed inside and out) had/has an extremely pleasant
character of its own (hence the triodes, see below) with a very nice tone
(even on the Chinese valves), superb air and detail and a very 'poised'
overall presentation.

At one stage I was switching (irritatingly :-) between DSOTM and a
beautiful vinyl rip of the same (from another regular here) and, despite no
attempt being made to synchronise the two sources, it was hard to split them
in terms of sound level and overall tonality. This indicated/proved that my
rig with the EAR was not a million miles different to someone else's rig
(same deck, asitappens, different cart and different phono) which was enough
to suggest the Ming Da was the Honda C50 to the two 70's Triumph
Tridents.... :-)

However, not being a devotee of the modern, universally compressed 'digital'
music that is so popular today, I don't subscribe to the theory that 'one
size fits all' and have been in the business of selecting amp/speaker
combinations to suit the various sources for a little while now. (What else
can you do, now that Tone Controls have been phased out...??) My suspicion
was that the phono stage was wanting to do finer things than rattle my
pictures with Bjork's 'Headphones' (which, bless it, it do to a degree!! :-)
so I put it onto the 2A3 SET to try summat 'completely different'....

Bingo! Different story, different picture!! The resultant sound (Joan Baez)
was quite *exquisite* - and one of the records I played was a 1960
original!! (Plenty of fizz but tonally as pure as the day it was made, thus
shooting a lot of silly theories you see spouted here about wear and loss of
treble *right* up the chuff...!!) All I'm going to say is that I could see
someone had been a bit 'quietly moved' by the experience!! ;-)

Unfortunately I hadn't got round to cutting my Line Stage into the equation
until this morning, but having done so now, I suspect the overall boost to
the sound would have found the bass Phil was looking for. (Also swapping the
valves on the Dynavox amp for JJ Tesla EL34s...)

It looks like a repeat session is on the cards....


NP. Benny Carter & his orch. 'Further Definitions'

(No 'recording' - he *is* in the room......!!!)

:-)

Keith G wrote:


OK, in case anyone is interested, a bit more information:

The object of the exercise was to check Phil's suspicions that the Ming Da
phono stage was a bit 'bass light' and to compare it directly with my
EAR834P phono which has a rep for being a bit fat-arsed and is generally
despised by one here who shall remain nameless. (Won't they Nick? ;-). This
was using a Shure V15 V xMR into B&W DM2As which have got a good bass if
well fed, can be a bit woolly if not and the bass from the Shure can bend
iron bars, if needed..... :-)

Must be a usage of "nameless" that I have yet to come across :-)

I was about to start with "despised" being a bit strong, but, no, you
are right, I think EAR phono stages are crap. That ok ?

When I mesured yours, it had a unneeded rumble filter, well that, or the
50hz EQ was wrong, and the response above 10k, fell like a stone.

IMHO, save your money, buy or build the WAD phono.

With all that, having not heard the stage in question, I have no opinion
on that, and how it compairs. There does seem to be two schools to valve
phono stage design, the "sod the RIAA, but it sounds nice to me" school,
or the (one I fit into), "get the RIAA as close as you can, design so
valve changes dont effect this, or can be dialed out, and then look at
the best sound" (valve op points, CCS, component choice, MC loading
values, power supply quality, RF rejection, all that sort of stuff).

However, not being a devotee of the modern, universally compressed 'digital'
music that is so popular today, I don't subscribe to the theory that 'one
size fits all' and have been in the business of selecting amp/speaker
combinations to suit the various sources for a little while now. (What else
can you do, now that Tone Controls have been phased out...??) My suspicion
was that the phono stage was wanting to do finer things than rattle my
pictures with Bjork's 'Headphones' (which, bless it, it do to a degree!! :-)
so I put it onto the 2A3 SET to try summat 'completely different'....


Out of interest, what the input impediances of the amps in question ?
That could well be making a difference. And maybe input capacitance,
depending on the circuit of the phono stage.

--
Nick

In article ,
Nick Gorham wrote:
Out of interest, what the input impediances of the amps in question ?
That could well be making a difference. And maybe input capacitance,
depending on the circuit of the phono stage.

I'd also be interested in the output impedance of the pre-amp. Does it use
cathode followers?

--
*Never slap a man who's chewing tobacco *

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:
In article ,
Nick Gorham wrote:

Out of interest, what the input impediances of the amps in question ?
That could well be making a difference. And maybe input capacitance,
depending on the circuit of the phono stage.


I'd also be interested in the output impedance of the pre-amp. Does it use
cathode followers?


That was my point...

--
Nick

Nick Gorham wrote:
Dave Plowman (News) wrote:

In article ,
Nick Gorham wrote:

Out of interest, what the input impediances of the amps in question ?
That could well be making a difference. And maybe input capacitance,
depending on the circuit of the phono stage.



I'd also be interested in the output impedance of the pre-amp. Does it
use
cathode followers?


That was my point...


From http://www.mei-xing.com/doce/pro20.htm

MM input level: 2.5mv
MC input level: 0.5mv
MM input impendence: 47k?
MC output impendence: 100?
MM signal to noise ratio: 91dB
MC signal to noise ratio: 86dB
Output impendence: 100K?

One day I will know what all this means!

On Fri, 03 Dec 2004 12:09:01 +0000, Phil North
wrote:

Nick Gorham wrote:
Dave Plowman (News) wrote:

In article ,
Nick Gorham wrote:

Out of interest, what the input impediances of the amps in question ?
That could well be making a difference. And maybe input capacitance,
depending on the circuit of the phono stage.



I'd also be interested in the output impedance of the pre-amp. Does it
use
cathode followers?


That was my point...


From http://www.mei-xing.com/doce/pro20.htm

MM input level: 2.5mv
MC input level: 0.5mv
MM input impendence: 47k?
MC output impendence: 100?
MM signal to noise ratio: 91dB
MC signal to noise ratio: 86dB
Output impendence: 100K?

One day I will know what all this means!

One thing this means for certain is that you shouldn't buy this
amplifier. At 100k output impedance, if you connect it to a power
amplifier with a cable whose capacitance is as little as 100pF, the
response will be 3dB down at 15kHz. This is most definitely NOT a
competently designed amplifier.

d
Pearce Consulting
http://www.pearce.uk.com

At 100k output impedance, if you connect it to a power amplifier with a cable
whose capacitance is as little as 100pF, the
response will be 3dB down at 15kHz. This is most definitely NOT a competently
designed amplifier.

Speaking in general and not about this product, You could make a case for 100k
out of a preamp into 1Meg on the tube amp side. The case you would make
(assuming short cables) is that you could then use a superior output cap of
smaller value and retain bass response. This is what I do - I use ten Russian
teflon .1 caps together to make 1uF. The teflon caps are so superior to others
I've used that I don't mind adjusting the rest of the parameters. This is
purely DIY, of course, and you wouldn't design this in a production model -
just as you say - because of system matching. But there is a theoretical side.

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

Don Pearce wrote:
On Fri, 03 Dec 2004 12:09:01 +0000, Phil North
wrote:
Nick Gorham wrote:

Dave Plowman (News) wrote:


In article ,
Nick Gorham wrote:


Out of interest, what the input impediances of the amps in question ?
That could well be making a difference. And maybe input capacitance,
depending on the circuit of the phono stage.



I'd also be interested in the output impedance of the pre-amp. Does it
use
cathode followers?


That was my point...


From http://www.mei-xing.com/doce/pro20.htm

MM input level: 2.5mv
MC input level: 0.5mv
MM input impendence: 47k?
MC output impendence: 100?
MM signal to noise ratio: 91dB
MC signal to noise ratio: 86dB
Output impendence: 100K?

One day I will know what all this means!


One thing this means for certain is that you shouldn't buy this
amplifier. At 100k output impedance, if you connect it to a power
amplifier with a cable whose capacitance is as little as 100pF, the
response will be 3dB down at 15kHz. This is most definitely NOT a
competently designed amplifier.


Cheers Don ;-)
When I bought this I expected two senarios:
1) The sound would be what I wanted and everything would be ok
2) It wouldn't be right and I would have to go and learn how to fix it.

I like learning stuff and it was so cheap and purdy I really dont mind
if it turns out to be 2).

Phil

From http://www.mei-xing.com/doce/pro20.htm

MM input level: 2.5mv
MC input level: 0.5mv
MM input impendence: 47k?
MC output impendence: 100?
MM signal to noise ratio: 91dB
MC signal to noise ratio: 86dB
Output impendence: 100K?

One day I will know what all this means!

One thing this means for certain is that you shouldn't buy this
amplifier. At 100k output impedance, if you connect it to a power
amplifier with a cable whose capacitance is as little as 100pF, the
response will be 3dB down at 15kHz. This is most definitely NOT a
competently designed amplifier.

The guy cannot even spell impedance correctly.

We engineers would all realise the output impudence
would be 100 ohms, or 1,000 ohms.

Patrick Turner.



d
Pearce Consulting
http://www.pearce.uk.com

Don Pearce wrote:
On Fri, 03 Dec 2004 12:09:01 +0000, Phil North
wrote:


Nick Gorham wrote:

Dave Plowman (News) wrote:


In article ,
Nick Gorham wrote:


Out of interest, what the input impediances of the amps in question ?
That could well be making a difference. And maybe input capacitance,
depending on the circuit of the phono stage.



I'd also be interested in the output impedance of the pre-amp. Does it
use
cathode followers?


That was my point...


From http://www.mei-xing.com/doce/pro20.htm

MM input level: 2.5mv
MC input level: 0.5mv
MM input impendence: 47k?
MC output impendence: 100?
MM signal to noise ratio: 91dB
MC signal to noise ratio: 86dB
Output impendence: 100K?

One day I will know what all this means!


One thing this means for certain is that you shouldn't buy this
amplifier. At 100k output impedance, if you connect it to a power
amplifier with a cable whose capacitance is as little as 100pF, the
response will be 3dB down at 15kHz. This is most definitely NOT a
competently designed amplifier.

d
Pearce Consulting
http://www.pearce.uk.com

I haven't followed the technical bits of this thread - so sorry if this
has been covered.

In HFW's Jan 2005 test of the Ming Da MC-7R preamp the output impedence
was found to be a problem and too high, causing buzzing. It was solved
by using resistors between the pre and power (a Quad 303), and the amp
was withdrawn from the market until the fault was fixed.

So there was an acknowledged design fault with this amp - it may have
been mirrored in the phono and you could have a pre-fix rogue. The
article does say that Ming Da were very good with email support - may be
worth contacting them.

For the technically minded I've scanned the 'measured performance' of
the amp.

-------
MEASURED PERFORMANCE

Preamplifiers commonly have a gain of x3, from CD input to line output.
The Ming Da offers more, x10, so to deliver 1V to a power amp it needs
100mV in -a relatively high sensitivity. There are no drawbacks to this,
since being a valve preamp it will swing 40V out, four times more than
most transistor jobbies. The volume control will need to be set quite
low, but as it is backed off input overload sets the signal handling
limit and this was greater than 6V, measurement revealed. It's more than
enough for all modern sources.
Bandwidth extended from 20Hz up to a very high 150kHz, within 1dB
limits. Below 20Hz there was a sudden and steep rise in gain to +10dB at
2Hz, possibly due to the way feedback has been applied. It wasn't a good
sign but the Ming Da seemed stable and able to cope. I strongly suspect
this will add a sense of depth or power to the sound, perhaps enhancing
'atmosphere', due to emphasis of subsonic aural cues. Distortion and
noise levels were satisfactorily low.
The Ming Da measures well, but its subsonic gain peak will influence the
sound. IMK

Frequency response 20Hz-150kHz
Separation 107dB
Noise -88dB
Distortion 0.14%
Sensitivity 100mV
gain x10
overload 6Vin/40Vout

(HFW Jan 2005, p.43)
--------

Rob