Monthly Archives: February 2016

The phono stage dilemma

While searching for my ideal preamp, one of my criteria was for this new preamp to have a built-in phono stage.  That turned out to be more difficult, as the only way I could find them was in older preamps, or in new preamps that were way beyond my budget.  I finally caved in to the idea of getting a phono stage.

Yet, which one?  I really wanted tubes.  I still do, to an extent.  But my choices in tubed phono stages was limited within my budget.  And when pressed for a choice, tubes might not be my solution after all.

My first candidate was a Jolida JD9 Mk II.  While build quality seemed acceptable, a few Internet forums mentioned that there were additional upgrades that could take the JD9 up to a higher level.  Upgrades include swapping in premium op amps, better output coupling capacitors, and HEXFRED rectifiers in the power supply.  Not to mention swapping in premium tubes.  I also would have installed my own mono switch on the rear panel.

While I like getting into the innards of electronics with soldering iron and voltmeter, the idea of hacking up a brand new phono stage (and voiding the warranty) did not sit well with me.  Once I did the math, I realized the Jolida would not have been a good investment.

The other candidate in valve land was the Pro-Ject Tube Box DS, which has the unique loading adjustment on the front panel.  It is nicely built, sure.  Yet like the JD9, I could not find any mainstream reviews of this model.  I found a killer deal on it, but decided to pass.  I do not put 100% weight in reviews, of course, but they are a helpful second opinion.

My luck came about by way of a lightly used Phonomena II+ by Musical Surroundings.  Mainstream press?  Yep, Absolute Sound had picked it as an Editor’s Choice.  Other reviews thought highly of it, and especially praised the depth and control in the bass.  Perfect.  It arrived within a week of purchasing it, and looked essentially unused.  The sound is, as you’d expect, phonomenal (sorry).

Loading is quite easy on the Phonomena.  A series of DIP switches on the rear can be set in many combinations to get LOMC loading where you need it to be.  For my Dynavector, I am currently at 59 ohms, but feel that I could probably nudge it down to 50 ohms to really smooth it out.

Running a MM cartridge, though, I have the option of two different resistive loads, and capacitive loads.  The only drawback is that MM loads are limited to 47k or 100k ohms; ear bleeders like the Audio Technica MM carts are happier with different loading, maybe in the 22k range.  The next available setting is 2k ohms.

For gain, there are 13 steps available from 40 to 60dB.

I did notice a bit of “rush” (faint white noise) when turning the volume way up.  I am going to inquire whether this is normal or not, and if a better power supply (than the small wall wart) would help that.  This phono stage uses so little power that a battery power supply may be an option too.

Overall, I have not had much chance to listen to it yet, but the sound is very clean and full-bodied.  If the soundstage was improved with the C-J preamp, this really locks it in further when playing vinyl.  I do want to tweak loads a little more, but it is really sounding nice at 59 ohms.

I will have more impressions over the coming week as I evaluate some high-quality vinyl.

Preamp upgrade: Conrad-Johnson PV-14L

It only took me 34 years, but I finally have a new (to me) preamp in the system, and I am finally a member of the “valve audio” club.  The PV-14L arrived two weeks ago, and I have been getting familiar with it.  My unit has had the “S2” upgrade, which features improved caps, Vishay resistors, etc., and a new spec for the tubes.

Having only seen photos of the front panel, I was afraid it was going to be silver.  Instead, it is a pale gold color, which looks nice with the engraved front panel.  Operation is by pushbutton, with most features available via the remote.  Switching and volume are done internally, so worries about oxidizing potentiometers is eliminated.

The tubes were changed out at some point, as the factory spec Mullard M8080s were replaced with the Philips ECG 6C4WAs. For a quick replacement, I ordered in a pair of Tung-Sol 6C4s which were marked for FAA use.  I have the M8080s shipping from the UK, as they are reportedly less microphonic than these 6C4s are.  The Tung-Sols do sound nice in the system, slightly less bright or “etched” sounding than the Philips pair.

One thing I have noticed with this preamp is that the imaging is rock solid.  Instruments are more clearly placed left to right in the soundstage, and vocals are spookily centered between the speakers.  Clearly my speakers are the weak point (for that “last mile” of improvement), yet I can still hear the differences.  One critique of this preamp was weak bass (boooo….), but the S2 upgrade cured that.  The bass is definitely weighty in the improved version.

It also appears to be a good match to the Nelson Pass-designed Stasis amp (Nakamichi PA-7).

The only thing it does not have is a phono stage.  But, that issue has been solved as well…

I will be back with a long-term update, as well as an update once I get the Cardas interconnects built.