Alright, so I went ahead and bit the bullet and will soon be taking delivery of the new Suppo Audio EL34 amp (I think maybe the first one). Joe was kind enough to send some pictures, I think it looks great, and it should be a lot of fun. My wife says I am somewhat addicted to buying tube related stuff so I hope she'll forgive me for yet another purchase.
Anyway, I'll be posting a review here on the stock model and hopefully Joe will post the schematic here as well so we can get started chatting about mods (because that's also part of my addiction). Joe says this EL34 amp is MUCH better than their first offering (which I really like) so this might be something great.
I've started work on a new chassis for my EL84 and will be tweaking it a little when it goes into its new home.
Anyway, I'll be posting a review here on the stock model and hopefully Joe will post the schematic here as well so we can get started chatting about mods (because that's also part of my addiction). Joe says this EL34 amp is MUCH better than their first offering (which I really like) so this might be something great.
I've started work on a new chassis for my EL84 and will be tweaking it a little when it goes into its new home.
Attachments
Oh boy, now I am REALLY confused on the tube complement on this amp. Joe, you posted the following in the other thread:
A quick clearify and correction about the 12at7 and 6cg7:
the tube we offer now is:
EL34 Silver version: shuguang EL34*4, 6DJ8*1, 6N6*2.
EL34 Platnium:shuang treasure EL34*4, 6N11*1, 6CG7*2.
the 6DJ8 ( 6N11) can be replaced with 12at7,12ax7 , 12au7 (need a swithing plate)
the diagram will be posted later.
The schematic you just put up has a 12AX7 in the front slot, two 6N1's next, followed by the EL34.
Now I'm really curious as to what is going to show up in my amp when it arrives...
A quick clearify and correction about the 12at7 and 6cg7:
the tube we offer now is:
EL34 Silver version: shuguang EL34*4, 6DJ8*1, 6N6*2.
EL34 Platnium:shuang treasure EL34*4, 6N11*1, 6CG7*2.
the 6DJ8 ( 6N11) can be replaced with 12at7,12ax7 , 12au7 (need a swithing plate)
the diagram will be posted later.
The schematic you just put up has a 12AX7 in the front slot, two 6N1's next, followed by the EL34.
Now I'm really curious as to what is going to show up in my amp when it arrives...
That EXPLAINS a lot- you need to put a Jap flag up ....
And since this "new" amp still doesnt seem to be on Suppo's site, when and if you get some decent pics of it from the outside and normal shots first (not just of the internals), please post them here.
Suppo Audio sells fully assembled amps. The pictures at the top are how they are shipped to you. See here.
My new EL34 amp arrived today and right off the bat, without even plugging it in, build quality and packing are outstanding. My amp arrived triple boxed, that's right, TRIPLE boxed, with roughly 2 inch thick layers of styrofoam around each box. Everything inside was in pristine shape with absolutely no shipping damage of any kind.
Build quality is MILES ahead of my EL84 from Suppo. No bent chassis plates, no loose screws, everything lines up like it should. Overall the amp is heavy and the OPT's look very beefy. That being said, they are nothing compared to the GIANT toroid. No one should complain about an undersized PT in this bad boy. Heavy duty power switch included along with a fused IEC socket. My only "complaint" is that the volume knob rubs ever so slightly on the front face plate. I'm sure that can be easily remedied. Also, the volume pot itself looks pretty skimpy but I won't judge yet. The amp comes with two sets of RCA's but no input selector switch so I'm not sure what the second set is for. It would be great if it could be used to hook up a subwoofer but I'm not sure on that one.
Tube complement is as follows: 4 EL34 tubes, 2 6N6 tubes, and 1 6DJ8. I did not receive the 12AT7 adapters Joe mentioned above so I'll have to email him about that. I've got TONS of tubes I think will work in the 6DJ8 slot (Russian 61N1-EV, 6H23-EV, RCA blackplate 6CG7, RCA cleartop 6CG7, Westinghouse 6922) but I'd love some confirmation from the experts. My understanding is that there are really no subs for the 6N6 tube (correct me if I'm wrong). I'd really like to try the Russian 6P3S-E (or 6N3C-E depending on your Russian) which I think is a great sounding tube in my Simple SE but I want someone to confirm for me that it will work well in this application.
Sound... that will have to wait until tomorrow. The amp arrived REALLY cold (probably sitting in a shipping warehouse overnight) so I'm going to let it come to room temperature overnight before firing it up. I'll post some impressions tomorrow.
Overall, just from looking at it, I'm very impressed/pleased. I think this amp is going to make some people with less efficient speakers pretty happy. Joe said he would post the revised schematic for the amp on/around 24 Feb when everyone goes back to work in China after the Spring Festival vacation. Love to hear some people's thoughts on modding this thing!
Build quality is MILES ahead of my EL84 from Suppo. No bent chassis plates, no loose screws, everything lines up like it should. Overall the amp is heavy and the OPT's look very beefy. That being said, they are nothing compared to the GIANT toroid. No one should complain about an undersized PT in this bad boy. Heavy duty power switch included along with a fused IEC socket. My only "complaint" is that the volume knob rubs ever so slightly on the front face plate. I'm sure that can be easily remedied. Also, the volume pot itself looks pretty skimpy but I won't judge yet. The amp comes with two sets of RCA's but no input selector switch so I'm not sure what the second set is for. It would be great if it could be used to hook up a subwoofer but I'm not sure on that one.
Tube complement is as follows: 4 EL34 tubes, 2 6N6 tubes, and 1 6DJ8. I did not receive the 12AT7 adapters Joe mentioned above so I'll have to email him about that. I've got TONS of tubes I think will work in the 6DJ8 slot (Russian 61N1-EV, 6H23-EV, RCA blackplate 6CG7, RCA cleartop 6CG7, Westinghouse 6922) but I'd love some confirmation from the experts. My understanding is that there are really no subs for the 6N6 tube (correct me if I'm wrong). I'd really like to try the Russian 6P3S-E (or 6N3C-E depending on your Russian) which I think is a great sounding tube in my Simple SE but I want someone to confirm for me that it will work well in this application.
Sound... that will have to wait until tomorrow. The amp arrived REALLY cold (probably sitting in a shipping warehouse overnight) so I'm going to let it come to room temperature overnight before firing it up. I'll post some impressions tomorrow.
Overall, just from looking at it, I'm very impressed/pleased. I think this amp is going to make some people with less efficient speakers pretty happy. Joe said he would post the revised schematic for the amp on/around 24 Feb when everyone goes back to work in China after the Spring Festival vacation. Love to hear some people's thoughts on modding this thing!
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Steve PM me first to offer help on improving the AMP, especialy on safty issues, and others.
I really appreciate his generous help. Now Steve is offering free testing following the EU reglation in his lab. Sure, he will comment on the performance too. I will prepare the a EL34 and "no vanished" Power Transformer, Output transformer, right schematic according to his requirement.
Thanks "tubesteve", a former telefunkung engineer.
Chinese has been too "so so" to everything for a long time. like you guys say "schematic shows 12AT7, but the AMP comes with 6DJ8"........ OH. What can I say.
so let's do it better.
I really appreciate his generous help. Now Steve is offering free testing following the EU reglation in his lab. Sure, he will comment on the performance too. I will prepare the a EL34 and "no vanished" Power Transformer, Output transformer, right schematic according to his requirement.
Thanks "tubesteve", a former telefunkung engineer.
Chinese has been too "so so" to everything for a long time. like you guys say "schematic shows 12AT7, but the AMP comes with 6DJ8"........ OH. What can I say.
so let's do it better.
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in the "old" times, currents, respective voltages have been shown without and with a signal present at a given power using a stabilized !!! mains power supply. the 6N6 is difficult to replace outside china or russia. the E182CC has different pinout......the 6DJ8 ( ECC88) is similar problem, its not an E88CC ( 6922) still manufactured by JJ. for mass-production and big markets tubes should be chosen which can be replaced by the current production. but: for the DiYers, this is not a problem.
That was my impression. The 6DJ8 can NOT be replaced with the 12A_7 series tubes; correct?
In this amp can the 6DJ8 be replaced with 6N1P-EV, 6H23-EV, 6922, and 6CG7? Also, would the Russian 6P3S-E work in place of the EL34?
I appreciate your input on this tubesteve.
the 12AX7 was designed for lets say 150mV from an RF detector. nowadays we have larger signals ( most ) up to 2VRMS ~ 5.7Vpp. so an 12AX7 can be easily overloaded.
An 6DJ8 is a frame grid tube with complete different properties than any 12AX... and was designed for TV tuners in the late 50s in cascode circuits. never be intended to be for audio..
normally a 6L6GC can work in a EL34 / 6CA7 place when plate/ G2 voltages are not more
than ~ 425V and G1 is around minus 38V, which is very common, also in UL mode.
if the tube is in autobias or in fixed bias, its a different story.
stupid comment now: put them in, and let your camera look ( infrared!) if plates or screen grids are glowing.
normally it can work at the voltages i said.
An 6DJ8 is a frame grid tube with complete different properties than any 12AX... and was designed for TV tuners in the late 50s in cascode circuits. never be intended to be for audio..
normally a 6L6GC can work in a EL34 / 6CA7 place when plate/ G2 voltages are not more
than ~ 425V and G1 is around minus 38V, which is very common, also in UL mode.
if the tube is in autobias or in fixed bias, its a different story.
stupid comment now: put them in, and let your camera look ( infrared!) if plates or screen grids are glowing.
normally it can work at the voltages i said.
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