PV-14L: Tubes and Tweaks

[Wildcat]

With the PV-14L settled into its new home, I'm thinking of doing a few minor tweaks.

This is the "S2" version of the preamp (factory upgraded, $600-ish), but it was shipped to me with a set of JAN Philips ECG 6C4WA tubes that were getting a little long in the tooth. This upgrade was done a few years back, so the Mullards that C-J put in it after the upgrade are long gone. The previous owner figured these 6C4s were used around half of their lifespan. I ordered in a pair of Tung-Sols and after about 15 minutes or so, I do hear a slight difference. Slightly less bright on top (not so "etched", if you will), but the bass remained full. Once these get a few hours on them, I'll have some impressions on them.

Once the next payday rolls around, I'm going to ordering a pair or two of the Mullard M8080s (which CJ recommends), along with a couple of other 6C4 pairs just for kicks.

One thing I noticed is how microphonic these tubes are. I have a couple of other tube pieces in other systems, and it seems that the 6C4 seems to rattle a bit if the C-J's case is tapped. Even pushing the volume buttons, I can hear them. The tubes did come with dampening rings, so that's a plus. I am considering using some isolation feet under the preamp, and possibly even dampening the lid with some sound deadener.

Just nitpicky little things, but nothing serious. This is a definitive step up from my previous preamp! Plenty of good listening ahead.

[jeffreybehr]

My MET1 uses a half-dozen M8080s. After I bought it many years ago, I tried MANY brands of 6C4s, but I tossed almost all because they were very microfonic. The Mullard M8080/CV4058 is a MUCH-better-sounding tube--typical-Mullard slightly warmish MR and excellent bass and treble. I didn't find many 'plain' M8080s, but the CV4058--the military-spec equivalent to the M8080--is findable on eBay. Buy 'em--they're worth it. Toss the 6C4s.

I use Herbie's Audio Lab Tenderfoots* under all my electronic equipment, and I use SoundCoat the Thicker** on all the ringing panels.


* 'Tenderfoot' is Steve Herbelin's trade name for these quishy feet, and I've never seen Steve use the plural form 'Tenderfeet', so I guess the plural is 'Tenderfoots'.
http://herbiesaudiolab.net/compfeet.htm

** http://www.soniccraft.com/product_info. ... -gp-p-4620 You might think it's expensive, but it REALLY works.

[Wildcat]

Good evening, time for an update! I finally received my CV4058s and indeed, not microphonic so far that I can tell. What I noticed about the tubes that came with the preamp was that when you tapped on the tube, you could hear the grids rattling inside. Not so with the CV4058s. I did like the sound of the Tung-Sols, but found them perhaps a bit more "dry" than these Mullards, which are still breaking in. I agree they have a "richer" presentation, sounding quite good with just about anything I threw at them today (from classical to Bill Evans to Stevie Ray Vaughan).

The SoundCoat does not seem that expensive for what it does--I might order some in soon, both for the preamp and the digital player. The Tenderfoots/feet/whatever are interesting! Still weighing my options there.