ULTRA RARE EL60--Earliest Version of Holland EL34
Current Matched 29 mA +/-1.3 CV% = 4% @ 400V Average (n =8)
the deviation within an octet is 2 mA or less!
Data from Calibrated (in March 2009 by R. Kennedy) Hickok TV-10A/U:
gM = 6750 +/-250 (CV% = 4%) for all eight tubes!! Min is 3800.
On an EICO 666 with NOS at 100%, these test 105% +/-3 across an octet.
http://www.audiogon.com/cgi-bin/cls.pl?accstube&1267460852&/Valvo-EL60-Daddy-of-EL34-Plug-Please see Agon ad. $850 per quad,
I have three quads available.
These are constructed to the military spec., insofar as:
1) support rods clamping the mica and dampening the tube to vibration and microphonics.
2) Rounded plates to dissipate heat.
3) Metal loctal base.
4) Pins connected directly to electrodes
5) Solid disc getter, signifying the earliest EL34 made in Holland
6) What appears as very active barium to absorb impurities from the vacuum by virtue that the tops of the tubes darken quickly, which is a good thing, I have read.
7) Ceramic spacers clamping the micas.
Remarkable construction for an EL34.
These are EL34--only with a loctal base. High quality loctal-to-octal adapters are provided.
In the RM9 MK2, these sounded quite remarkable.
True-tested NOS. Current matced at high voltage. gM matched. Emission matched. Tested in a refined, high power amplifier. See the Agon link. Here is a link to read a bit more.
http://digilander.libero.it/pasqua49/Guide%20to%20the%20EL34/guide%20to%20EL34%206CA7.htmSee link below for a nice picture of construction.
http://www.radiomuseum.org/tubes/tube_el60.htmlI guarantee compatibility with the EL34 and no issues--and--reproducible data. The included adapters are EXCELLENT QUALITY.
My feedback on Agon, Ebay and HeadFi is under this same name.
Thanks
SUMMARY EL60Base Loctal-9-Pin (B9G) (Codex=Ya)
Filament Vf 6.3 Volts / If: 1.3 Ampere / -: Parallel, (AC/DC)
Description Power output pentode, launched mid 1948 by Philips
Many years after the F443N the EL60 appeared as a new 25 W power output pentode, now as all-glass tube with the 9-pin "key"(Loktal)-base as the EF50. As this wasn't accepted by the market, one year later it became provided with an octal base and appeared then as EL34, which is in production up to today. [Jacob Rosch?,15 May 2003]
