| spektraldata |
Hello all...
One of my "dream" is to have and build a tube amplifier...
I have already (someone give me) 3 ECLL 800...
So if someone know know where to find some shematic for a
diy around this tube...you 're welcome ! ;)
Sorry for my english...THX |
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| Giaime |
This is it, assuming that:
1) you've read the safety guide about the high voltages. Look at a thread here, in this forum, that's sticky.
2) you know how to build a 250V supply.
I personally would wire the pentodes as triodes... ;) |
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| spektraldata |
Thanks...
Yes I've work in electronic fabrication and repair
But only in TV section so I don't know a lot of thing in tube...
Have you got shematic for the power supply ?
Is this amplifier good quality ?
Can you tell me the detail of the component ?
(watt of the resistor...value of condensator...)
I know where to find the out transfo and power...
Last question...does this schematic need a preamplifier ?
Best regard |
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| spektraldata |
Yes...i need to know ...
The type and value of the condensateur...
The power of the resistor
If i need and preamplifier wich one ?(to work with CD player)
A schematic of the power supply
The 6.3V in DC or AC ?
How many ampere for high voltage and hot circuit for one tube ?
Can I test my tube before begin to build ?(i think no but...)
If you can answer this...you 're the best....:D
I will put a tempo on high voltage...is it good?
sorry i need all the detail to sart my project ....and learning...
thanks a lot :cool: |
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| Giaime |
| quote: | Originally posted by spektraldata
The type and value of the condensateur...
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0.47uF 400V polypropilene will do good, but in parallel of that 180ohm resistor use a 100uF electrolytic of good quality.
| quote: | Originally posted by spektraldata
The power of the resistor |
1k and 1M ones will be good at 1/4W, 150k is better 1W and 180ohm will be I^2*R = 0.026*0.026*180 = so small, put 1W and your're fine.
| quote: | Originally posted by spektraldata
If i need and preamplifier wich one ?(to work with CD player) |
Mmmmm I think you need one. You need a gain of 3 or 4... do a search for the various linestages you'll find on the net.
| quote: | Originally posted by spektraldata
A schematic of the power supply |
That's easy.... do a search for the various power supply schematics of other amps, or try to design yourself.
| quote: | Originally posted by spektraldata
The 6.3V in DC or AC ? |
Either will be good, however DC will be quieter.
| quote: | Originally posted by spektraldata
How many ampere for high voltage and hot circuit for one tube ? |
You'll need about 70mA per tube (both pentodes and the triode), look for 80mA to have better regulation. The 6.3V supply has to be at least 600mA per tube.
| quote: | Originally posted by spektraldata
Can I test my tube before begin to build ?(i think no but...)
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With a tube tester, yes... ;)
| quote: | Originally posted by spektraldata
I will put a tempo on high voltage...is it good?
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You mean a time delay? That's good... it will make the cathode warm before applying the high voltage. It will longer the life of the tubes. |
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| Steven-H |
I just stumbled upon this thread (thanks to Dave for the idea...). I'm going to try to toss this together el Cheapo. Here are my thoughts on the iron:
Power: Hammond 261G6 (250v 130mA, 6.3v@2A)
Choke: C354 Dynaco (1.5H @ 58ohm, 200mA)
OPT: Hammond 1609 (10k)
The total for the iron comes out to be about $110
The PSU is a SS CLCRC design, using 1N4007 diodes in full bridge. C1=120uF, C2=120uF, C3=100uF. R1 = 470 ohm, 15W
I am still undecided about the heaters, although I think DC may be the way to go...Dependant upon where I can find these tubes, I hope to get this done under $200....
Thoughts ?
-Steve |
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| Steven-H |
| Yes - I know...Which is rather unfortunate. But if you had the tubes on hand.... |
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| Klimon |
Oops, overedited my last post...
In Europe you could try to find an old radio and pull them but in the US they'll be scarce.. I've got the parts from a radio, should be a nice little project (still adding a few grey hairs:D )
Simon |
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| Steven-H |
Simon,
Thanks for the help ! I was also thinking of an ECC83/12AX7 driver. That said, that is beyond the rating of the power transformer I selected (it is rated at 130mA), so I will have to find something abit hotter - which unfortunately means larger. I was trying to make a nice small unit; any suggestions on some nice small 250v, 150mA, 6.3v@2A units :D
Thanks !
Steve |
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| the_manta |
These tubes were designed in the "late years" by SEL-Lorenz especially for the new generation of radios. It was possible to built a stereo Push-Pull Amp in a very small cabinet.
But production was ceased early because of the Transistor going his glorious way.
Nowadays these tubes are getting rare and there are thousands of radios out there which need them. And, there is no way to use another tube or to built an adapter or something. that's because of the little triode in there with a µ=1,2. You won't find a substitute
These facts show that its not wise to use that tube for new projects. It's just senseless....there are many nice tubes out there which are new in production.
A few days ago, the new KT66 was released by JJ
It's an excellent tube, an exact copy of the original GEC. Jogi, the owner of the Röhrenbude sent some original GEC's to JJ, they cracked the bulb and copied it. A brave decision, but it was worth its price
Regards, manta |
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| planet10 |
I have at least one schema for ECLL800 (and a bunch of the tubes). The amp i'm canabilizing used a 12AX7 variant as a driver.
The C in the ECLL800 is a unity gain phase inverting tridode stage to drive the grid of the 2nd tube. The screen grids are tied together inside the tube so you are limited to building a push-pull pentode amplifier of 6-8 W. If you have enuff gain in your preamp (ie something like 6-10 V (Bottlehead foreplay is a good example)), you could have yourself a 2 tube, stereo push-pull amplifier.
dave |
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| ilimzn |
| quote: | Originally posted by the_manta
[B]These tubes were designed in the "late years" by SEL-Lorenz... its not wise to use that tube for new projects. |
I vocally agree!!!
ECLL800 were only made by this single manufacturer (they did come with different labels but were all made in the same place) and they are VERY rare, and getting more so. These are best used to restore the old radios they were used in, for which purpose they can be sold on eBay or somewhere like that, and you get enough money for them to get a whole set of tubes for an amplifier. |
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| Eli Duttman |
Steve,
I also think you should find a different design. If you had the tubes in hand, it would (perhaps) be a different story. Look at the schematic closely. In (sic) pentode mode, power O/P is 0.5 W. Low distortion and reasonable damping factor require triode wiring, which will reduce O/P to about 0.25 W. Do you have the 108+ dB. SPL/W./M. speakers needed?
I'm VERY cheap and look for solid performance at modest cost. May I immodestly suggest "El Cheapo". For not much more than $200, you will get a NICE amp that mates with 94 dB. efficient speakers. If a CDP is the source, a line stage is not needed. Read the complete "saga" here. |
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| Klimon |
| quote: | | In (sic) pentode mode, power O/P is 0.5 W. |
Why is that?
--
I agree ECLL800 probably won't give same quality or bang for the buck as other tubes; it is something very different though.
There was a circuit with ecll800 in glass audio
Simon |
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| planet10 |
This is the output stage from a Nordmende ECLL800 receiver.
I've been simplifying the channel at the top (nuking tone controls, etc). The feedback goes to the stage previous to what is shown. The triode sections of the mult-purpose front-end tubes are close to 12AT7/ECC81
dave |
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| planet10 |
| quote: | Originally posted by Eli Duttman
low distortion and reasonable damping factor require triode wiring |
I don't think that it is possible to wire this tube in triode.
Also. you can only talk about reasonable damping when the speaker is included in the equation... speakers with XOs tend to want amps with higher damping factors/low OP imp, but many a full-range system will benefit from low damping factor/high OP imp.
dave |
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| Eli Duttman |
OOPS, I goofed! I locked in on the upper left corner of the schematic provided. That data is for the small signal triode. the PP power pentodes are good for about 8 W.
Dave D. (planet10) is correct. Because the 2 screen grids are tied together, only pentode mode is available.
I stand by my advice to find something else. I priced the ECLL800 at RES. They are 60 bucks each. :bigeyes: Leave that scarce and costly NOS for OEM replacement. A full set of tubes for "El Cheapo" costs less than a single ECLL800. :D |
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| Steven-H |
Thanks Gents.
I have heeded your advice and ditched the idea. I now am looking into the 6T9 tube; which can be had for $3/ea :D
Hammond 269JX PT with Edcor outputs most likely....
Thanks !
Steve |
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| planet10 |
| quote: | Originally posted by Eli Duttman
stand by my advice to find something else. I priced the ECLL800 at RES. They are 60 bucks each. :bigeyes: Leave that scarce and costly NOS for OEM replacement. A full set of tubes for "El Cheapo" costs less than a single ECLL800. |
I agree on the look for something else... if the ECLL800 is selling for that much i think that mine might go up for sale... If i can get 1/2 NOS for my used ones i could fund another El Cheapo.
dave |
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| ilimzn |
| Hehe I have a number of brand new ones in their original boxes :) |
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| planet10 |
Let's conspire not to sell them at the same time :)
dave |
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| ilimzn |
| Don't worry, they are not going anywhere with the prices going up as they are... although, I suppose i could arrange a trade for a couple of nice OPTs :) but we're getting dangerously off-topic here :) so I'll stop... |
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