Good Cartridge for Pioneer PL-10

[Poindexter]

Wo, dsav,

A phonostage comprised entirely of 6GK5s and 6T4s!  We've talked; these are my fave suspects, I have hundreds of them on my shelf, and accoutrements du project!

You da bomb!

P

 

[dsavitsk]

A phonostage comprised entirely of 6GK5s and 6T4s!

I thought you'd enjoy that.

SY says, circuit wise, it is pretty close to his phono stage, so I figure I did alright in the design.

b/t/w/, in addition to your favorite tubes, the PS also uses your Amveco toroid trick, so really this project is just channeling you

 

[sreten]

sreten,it is true that a MP-110 is more expensive than AT71E,
but being cheaper does not necessarily mean that the AT is better
value.I believe more expensive cartridges than AT71E can be of
equal,even better value,depending on the sound quality they offer
for the price.$80-100 is not too much for a turntable like the
PL10/12 IMO.Also,if Grado leans on the warm side of neutral as
said,I think this could be very welcome for a turntable like this.
The Shure is also another nice one and has a nude tip too!!!

Hi,

I'm not familiar with the MP110, I do know the MP11 which is
not a lowish compliance cartridge. The MP10 would suit better.

You are welcome to your opinion. My experience of AT's correctly
loaded is that more expensive (but technically similar) cartridges
do not sound particularly better, different yes, matching matters.

The Grado's do sound different, as would the MP110 (MP11 like).

I have completely rebuilt a PL12D, and IMO one should not take
a standard PL10 too seriously, YMMV. The M97xE (used with its
damper) looks very good value at $55 - not a bad choice.

For $100 you can get the nude line contact AT440MLa :
http://www.lpgear.com/Merchant2/mer...e_Code=LG&Product_Code=ATC05&Category_Code=A3

Which is way too good for a PL10 IMO, and far better than a MP11.

/sreten.

 

[Panicos K]

Hi sreten,the MP-110 has slightly lower compliance than AT95E(LP Gear info) so it will not have any problem with the PL10 or similar arms.I mentioned it as an option with a smoother and less harsh sound than AT95E.No doubt the 440MLa's specs are impressive,but I don't think it will be a good choice for the PL10.In fact it will be a very bad combination/matching with those compliance figures.Also,the "family" AT sound will remain mostly unchanged,despite a better resolution and tracking when mate with a more suitable tonearm than that of the PL10.

 

[sreten]

Hi,

If the MP110 is like the MP11 then the paper
compliance specifications are fairly meaningless :

http://www.tnt-audio.com/sorgenti/nagaoka_mp11_e.html

The MP11 has a seemingly-supple suspension, the quoted static compliance being 20*10^-6 cm/dyne, and the dynamic one 8*10^-6 cm/dyne. In real life the 6.8g mass combined with the modified Rega arm resulted in a measured resonance at 7.5Hz. Calculating backwards this would imply a dynamic compliance of 20*10^-6 cm/dyne, and an even higher static one! Either the specifications are wrong, or there is something fishy going on with the manufacturing tolerances. Let's be lenient and assume the former, meaning that ideally a lighter tonearm should be used. However, the resonance is fairly well damped and the MP11 proved to be quite easy-going in use. It was certainly more stable and less jittery than could be expected, contrary to under-damped designs like some Grados.

Compliance specs of the MP110 and MP11 are identical.

I suspect the MP110 might be somewhat lower compliance
than the MP11 but still nowhere near as low as an AT95E.

I'm not suggesting for a second the AT440MLa should be used
in the PL10, though I cannot see a compliance mismatch.

/sreten.

 

[Panicos K]

MP-110 behaves much better than the discontinued MP-11 in terms of damping and tracking.However,with a price of $55.50 and damper plus a good stylus and known sound,my choice would be the Shure M97XE

 

[sreten]

MP-110 behaves much better than the discontinued MP-11 in terms of damping and tracking.

Both are very good in the MP11 so how can they be "much better".

/sreten.

 

[Panicos K]

There is always room for improvement Seriously,the 110 is more stable in the groove with higher mass tonearms to my experience.It is not a MP-11 in a different colour

 

[Poindexter]

dsav, guys,

Do I understand correctly that calculation for resistance in the pole filters must include the Zout of the preceding stage?

Aloha,

Poinz

 

[dsavitsk]

Do I understand correctly that calculation for resistance in the pole filters must include the Zout of the preceding stage?

Yes. So in mine, with 47n and 1n caps, according to Hagtech's calculator, in the first stage I needed a Zout of 61K and a resistor in series with the 47n cap of 6K7, and in the second, 72K and 3K2.

So, the Zout of the first stage is about (rp + (mu * rk)) which is in the ballpark of 5400 + (78 * 56). Added to the 61K resistor, this is a tad low, but my 6GK5's are a little higher than spec on the mu and running at a slightly low current, so I figured (without measuring) that this made up for the difference. If the current were increased to 12 or 14mA, I might move to a 60R resistor in the cathode, though I am doubtful of any audible changes.

I might add that overall gain might be a little high for me -- I use TVCs as a preamp and thus can only attenuate so far. I am finding that I am listening at the lowest volume which is comfortably quiet, but I can't listen really low. The caveat to that is that I never listen to anything very loudly.

 

[Poindexter]

Well, hold the phone.  I have a little tube test breadboard that I can rerig up to test for the Zout of the stage.  I'm soldering right now, 6GK with 51Ω on the cathode, a 10M45 on the plate.  I'll put a pot in the output test and see where the half-voltage load is.

I thought the CCS would lower the Zout, but looking on the web references, maybe not.  Right now I have 332Ω set resistance, which should be about 7-8mA, which will get us up on the slope of the curve enough for a good reading.

P

 

[dsavitsk]

I thought the CCS would lower the Zout,

If Rk is not bypassed, it should be rp + (mu * Rk) || Rp, and with a CCS Rp is essentially infinite.

 

[Poindexter]

Yup, that's what I have, for a resistively loaded amp; but I somehow got in me tiny brain that the virtue of a CCS was that combination of insanely high Rdyn, and the ability to still source current.

The test will tell.  Right now, I'm having a small headache biasing the device up properly.  If I actually ground the grid, everything works coolio, and with Rset at 280Ω, I'm getting about 10mA and 30V on the plate, from a 120V B+.  If I unbypass the 100K g-k resistor, the grid actually sucks down to -1.5V, and I only draw about 3mA.  Strange.

Additional research seems indicated   :^) .

P

 

[Poindexter]

BTW; if you're using the Hitachi 6GK5s, you might try the Mullards in your situation.  They sound to my ear nearly identical (maybe just a smidge clearer), and a cascaded pair of them will give you about 28% or so less gain.

P