La Figaro 339
Oct 7, 2013 at 4:51 PM Post #2,026 of 6,903
I always wondered what is really the output Impedance of the LF339...? The manufacturer on your website did not specify this clearly, as we know for OTL's, parameters like internal output impedance is very important and is worth to know it, there is No transformer to match the impedance of the load, so to satisfy my curiosity I guess not only my, finally found some time to do some measurements.
 

 
Edited,
 
Summing up and given the fact that the amp does not have a negative feedback the output impedance of our amplifiers is satisfactorily low. Of course! it depends largely on the type of tubes which we will use on output, no doubt TS5998 have the lowest in mid rage about 23 Ohm and about 29 ohm at very low end 20Hz and right behind her are 7236TS & Cetron all can work without fear with the 32 Ohm Grado family. But even Chinese 6N13PJ is not too bad with the average impedance about 38.5 Ohm and peak about 43 Ohm at 20Hz, no problem they will fit with the 50 Ohm and Up cans.
 
Oct 9, 2013 at 5:51 PM Post #2,027 of 6,903
It's been hard finding a pair of mesh tubes, any idea where to look?
 
I've even been scouting Yahoo Auctions and Taobao and come across some rarer options along the way, like Toshiba/Mazda, Hitachi, Ultron, Ten, NEC and perhaps more but I forget.
 
All of them are the alternative looking ones like the one posted earlier:
 
 
this looks gorgeous
 


Bit of an unknown quantity, as no one seems to have tried these ones? Instead I'm focussing on finding an American pair, such as the famous Tung-Sol, which are similar (or the same) as the RCAs that Ultrainferno has or these Arcturus ones I came across:
 


Found a pair of TS finally the other day but they were dinged up…
 
*ultron ones just appeared on ebay, if anyone's looking for 15 of them hehe http://www.ebay.co.uk/itm/15-X-6SJ7-GT-ULTRON-NOS-NIB-TUBES-/310765636004?pt=LH_DefaultDomain_0&hash=item485b1349a4 
 
Oct 13, 2013 at 7:00 PM Post #2,030 of 6,903

 
Received my last package with tubes this time I ordered some triodes for input stage duty to test how is sounds like with my modded La Figaro 339, so far I had only one pair of CV1067 to play on it the rest are all known pentodes including very famous mesh TS 6SJ7GT best so far. CV1067 is quite good very similar to RCA “ redhots” with a bit wider saundstage, natural midrange and a little bit better saturation of the treble, but only if accompanied by TS5998 or 7236 or probably any medium (mu) equivalent, with any low (mu) power tubes like 6AS7G, 6080..only average. The Raytheon 6J5WGT is ruggedized military/industrial versions of the 6J5GT, medium gain, the electrical characteristics of 6J5 match half of the 6SN7 dual triode it finds use in many classic and exotic valve amp such as Audio Note, is very linear and has a decently low plate resistance as a driver tube it has sufficient gain for a two stage design of 339. How it sounds?  Immediately you notice is louder this is due to the higher gain, tubes like 6as7g, 6080...they are gaining the most, the response, the drive is improved, soundstage is wide, maybe a bit too wide therefore vocals withdraws into the interior and up range is highlighting more then midrange but the quality of treble is one of best I heard so far.
  

And at the very end Marconi L63 I was lucky because I was looking for a pair of GEC's L63 but the seller did not have them but instead offered me MWT (Marconi's Wireless Telegraph) NOS in their original boxes, BTW very rare and costly in those days. They are of similar build to CV1067 and can be used interchangeably but the sound produced by these tubes is a different league in a blind test would point to TS 6SJ7GT the L63 have a little bit warmer and tangible midrange the highs as good as mesh 6sj7gt with the rest of the range very pleasant to listen.
But Marconi's L63 in conjunction with Bendix 6080WB and HE-500 is Rocks!  is screw**g  good...is Rocks!
basshead.gif

 

 
P.S Please note it applies only to the new version of LF339 with 6c5 input stage.
 
Oct 16, 2013 at 6:29 PM Post #2,035 of 6,903
  6C5C adaptation EF80. EF86
 

It been three years since 339 was released, during that time passed several modifications, this is his latest 6c5c variant which seems to be a more comprehensive with these adapters(6c5c>>>EF80,800 & 86) for a potential customer but it seems to me that since that time people get used to the sound of pentode in its original version and some of these tubes have grown to become the "iconic" fabled like TS6SJ7GT peculiarly mesh plate variant, for its sound qualities but also for appearance and beautiful glow. The question is are you planning to do the adapters (6c5c >>> 6sj7,5693...etc.) too or you already did and have them on offer? It could be a more comprehensive than it is.
Thanks.
 
Nov 3, 2013 at 4:57 AM Post #2,036 of 6,903
Wall-E, the smoked glass L63 you got are fabulous! I agree with you Bendix 6080 with my bottle shaped smoked marconi L63 are simply outstanding!

 
Nov 3, 2013 at 8:53 AM Post #2,038 of 6,903
Hey Ultra! I think those are M3 thread, but it's more to do with the spikes you use. I don't remember but I got the largest solid aluminium feet I found on eBay. Little expensive though (30$ without shipping from US) but all the chinese ones were either too litle for my taste, or grossly audiophile feet with silly prices. Carefull though because 4 feet will get you some trouble in leveling while only three feet is not stable enoug for this heavy amp.
Anyway they are some nice and cheap quality alu feet on the bay and they almost always sell the screw that goes with it. It's not an easy mod, you have to drill hole if I remember correctly, and steel is not your friend ;p
 
Nov 4, 2013 at 10:27 AM Post #2,039 of 6,903
I have my 337 back...the guy who bought it from me got fired and almost begged me to take it back..and as i am a nice guy (and luckily dont have money problems) i accepted it..he was sooo happy..so i guess i have a better chair up there in the stars now :wink:

But seriously..as i know the 337 is not wellknown (a big disgrace!) its not easily sold...
So i decided to sell the TS tubes seperately and sell the 337 (last model 2010) with the svetlana's (rare vintage 70ties) and the rca 5693 red hot in it

And now the interesting part for u guys:

My MATCHED pair of 5998 (chatham) and my super rare TS 6sg7gt mesh plates (totally silent!!!!) tubes i will be selling seperately..both are MATCHED pairs and were NOS when i bought them (5988 has 200hours, mesh plates 250)

For the 5998 i want 200usd for the meshplates 60usd
And sell the 337 for the rediculously low price of 450 euro!

This is a great deal guys..this amp is good as u guys know...especially with the senheiser hd650/600, the hifiman he400/500 and grados! And the tubes..well..no words needed!
 

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