Current favorite is the Svet 811-10, I love 'em 
8 watts SE, excellent sound, very cool thoriated tungsten cathodes (really lights up the room at night), all for $80 a matched pair.
Only downside is the required transformers are beefier than a comparable 300B amp...my monos weigh 40lbs apiece.
8 watts SE, excellent sound, very cool thoriated tungsten cathodes (really lights up the room at night), all for $80 a matched pair.
Only downside is the required transformers are beefier than a comparable 300B amp...my monos weigh 40lbs apiece.
Glowbug said:Current favorite is the Svet 811-10, I love 'em
When did that happen? I thought the SV 811-xx and SV 572-xx were dead product. Are they back in production? Looking for potential alternatives to a triode-connected 813...
http://www.southwestelectronics.com/svetlanatubes.html
KT77 and S11E12
KT77: 16 euro/pc. : http://www.ae-europe.nl/buizen_jj.htm
I just bought some S11E12 tubes (=12E1, CV4060), KT88 lookalike. I hope this is going to be my next favourite tube in a pentode amp with local feedback and regulated screen supply. Any schematics or favourite operating point or advices for this purpose ?
TJ 300B meshplate is of course a nice tube.
KT77: 16 euro/pc. : http://www.ae-europe.nl/buizen_jj.htm
I just bought some S11E12 tubes (=12E1, CV4060), KT88 lookalike. I hope this is going to be my next favourite tube in a pentode amp with local feedback and regulated screen supply. Any schematics or favourite operating point or advices for this purpose ?
TJ 300B meshplate is of course a nice tube.
the_manta said:
Hi Simon, nice idea to use the EL38. Not common, really. Any experience with it already? I, too, love it a bit the uncommon way. Had very good experience with EL 36 and 7027A - very clear sound even in pure pentode operation, thus a good compromise between sound quality and power consumption... ;-). This amp runs for about 16 years now - see pic .... Experience in this mode with EL34 or 6L6 weren't so good, rough sound, obviously need triode or at least ultralinear operation to sound well....
Last year's project was a circlotron with 2x 6C33C, not quite easy to handle technically (hum problems, complex circuitry), but sounding..... GREAT!!!!..... Never heard such a clear and powerful bass..... Still need to do some fine tuning.
Current project: A 2x E130L PP in enhanced triode mode - driven on the screen grid, grid 1 for biasing only..... Driver will be a ECC99 - PCL85 mu-follower......
Planned for the future: A 833A SE in A2 mode driven by a EL519 ........ already collecting parts....
Good success! And let us know about your experience with the EL38!
Uli from Saarbrucken, Germany
EC8010 said:
Never have had any hum problems with this amp. Mains transformer is quite oversized to reduce stray fields. Distance between output transformers and 50Hz-irons obviously is big enough. And I'm listening on ACR 96db-horns...... They are completely quiet even with your ear directly in front of them.
And hum coupling between mains tr. and choke isn't of any importance, since the choke sits in the AC (!) line before the gas tube/silicon diode hybrid bridge rectifier - I found this to be a very good way to reduce current spikes gas tubes are sensitive for..... Gas rectifier is a Raytheon CK 1006 noble gas tube, which runs for more than 10,000 hours now...... Choke is from a 150W mercury arc lamp for industrial illumination.
Hi Uli !
Nice Amp ! Looks really good.
I like these rugged metal chassis. Wood is OK, but not my favorite.
I tested the EL38 in maaany ways in my wild-looking test circuit here:
The EL38 is connected as Pentode. I like fast neutral sound with the hard and powerful bass. And actually I wanted a pentode Driver, a EF40, but had many problems due to the high internal resistance of the EF40 and the feedback. I tested maaany ! Bootstrapped EF95 with a EF80 cathode follower...sounden terrible. EC88, sound wasn't bad, but I built a transmitter at 4Mhz.... EC88 was hard to get silent and the amplification factor was too low. Finally I ended up with the 5751, systems in parallel. Sound is nice, not the sloppy Bass of a SET Triode with no Feedback.
Since you speak german, it's easy for you to read the story here:
http://f23.parsimony.net/forum45451/messages/185216.htm
SO far my Experiences are good with the EL38 on the Hammond 1627SE trannis. Huuuge deep bass, very neutral midrange (not these beautiful lovely mids which get boring after a while). The highs are a veeery little bit weaky, but thats typical for the big rugged Hammond output transformer I have no problem with that.
The EL36 is a nice tube ! You run it in Pentode, nowadays I would connect them as Triodes, since I saw the amazing curves (Oh no.....the prices will now explode on Ebay...
)
833..hmmmm to many people have already built an Amp with that tube...It's expensive and the socket is a problem. I have a pair of 813 and GK71...Anytime I will use them for sure.
Enhanced is a nice operation Mode, but it's hard to get curves for that, so you will have to draw your own.
Next Project..hmm let me think Till now, I have only built SE's so next Project perhaps a PP with 6336. But I have also plans with AD1, RE604 and the cute looking 814.
I'm 17 years old and go to school, it's hard to find enough time for my hobbies, but i won't give up.
Regards, Simon
Nice Amp ! Looks really good.
I like these rugged metal chassis. Wood is OK, but not my favorite.
I tested the EL38 in maaany ways in my wild-looking test circuit here:
An externally hosted image should be here but it was not working when we last tested it.
The EL38 is connected as Pentode. I like fast neutral sound with the hard and powerful bass. And actually I wanted a pentode Driver, a EF40, but had many problems due to the high internal resistance of the EF40 and the feedback. I tested maaany ! Bootstrapped EF95 with a EF80 cathode follower...sounden terrible. EC88, sound wasn't bad, but I built a transmitter at 4Mhz.... EC88 was hard to get silent and the amplification factor was too low. Finally I ended up with the 5751, systems in parallel. Sound is nice, not the sloppy Bass of a SET Triode with no Feedback.
Since you speak german, it's easy for you to read the story here:
http://f23.parsimony.net/forum45451/messages/185216.htm
SO far my Experiences are good with the EL38 on the Hammond 1627SE trannis. Huuuge deep bass, very neutral midrange (not these beautiful lovely mids which get boring after a while). The highs are a veeery little bit weaky, but thats typical for the big rugged Hammond output transformer I have no problem with that.
The EL36 is a nice tube ! You run it in Pentode, nowadays I would connect them as Triodes, since I saw the amazing curves (Oh no.....the prices will now explode on Ebay...
)833..hmmmm to many people have already built an Amp with that tube...It's expensive and the socket is a problem. I have a pair of 813 and GK71...Anytime I will use them for sure.
Enhanced is a nice operation Mode, but it's hard to get curves for that, so you will have to draw your own.
Next Project..hmm let me think
Till now, I have only built SE's so next Project perhaps a PP with 6336. But I have also plans with AD1, RE604 and the cute looking 814. I'm 17 years old and go to school, it's hard to find enough time for my hobbies, but i won't give up.
Regards, Simon
I have used the 6L6GC most often (quite a few dozen of them). Preference is because of efficiency: 30W of anode dissipation and only 0,9A heater. But these days one has to watch out - with respect, the Russians can be rather free with allocation of numbers. Several 6L6GCs are no more than ...GBs (lower dissipation). But I interested in the KT77 - never seen one.
Since it is Christmas time and other pictures have appeared (some pretty neat jobs there!) I will try with mine:
Since it is Christmas time and other pictures have appeared (some pretty neat jobs there!) I will try with mine:
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