Output transformer
My friend
The output transformer Is made in a transformer factory here in Brazil. I make the calculus and the industry build for me.
But I will get a Edcor GXSE10 for a comparation...
Aldovan
Man I just love small and cheap amps nowWhich OT are you using? I am mightily impressed with the XSE series from Edcor, tho not with pentodes. (triodes drives them wonderfully)
My friend
The output transformer Is made in a transformer factory here in Brazil. I make the calculus and the industry build for me.
But I will get a Edcor GXSE10 for a comparation...
Aldovan
Super cheap...?
1. Change E180F to 6AU6, there's boatloads of these around and the price is good. More abstract choices abound, especially oddball triode-pentodes. Nothing wrong with letting one half of such a device go unused, if you only need one. And hey, you could add a "tube roll" switch (at moderate price increase) to change between the triode and pentode in the envelope!
2. Replace LED with resistor. LEDs cost money.
3. Don't parallel caps: besides being a useless procedure, they waste space. Additionally, don't use name-brand capacitors; end-users know the sellers simply pump up prices artificially on components that have no audible effect whatsoever. I haven't seen many capacitors any cheaper than Cornell-Dubilier DME series, plus, they're really, really compact. Absolutely perfect for coupling use.
4. 6W6 is an oddball choice, but makes a reasonable triode. Prices may vary. 6V6 would be more common, and is in current production [I think..??], but price varies accordingly with market. YMMV. Rolling options include... pretty much any comparable pentode, certainly the 6Y6 mentioned, but also 6K6, 6F6 (a bit lower gain), higher voltage variants like 12L6, and even miniature variants thereof, like 50C5, etc.
5. The output transformer isn't specified, but do make sure to grudgingly spend a couple bucks there, you won't regret it.
6. Dump the series choke, it's expensive dead weight. Yeah it makes things quieter, but the thread title is "Super cheap amplifier" after all!! All right, you probably do want the choke in there, but only grudgingly.
7. We've already got silicon diodes, dump the damper. Also, less filter capacitance could be used, at expense of ripple levels.
Tim
1. Change E180F to 6AU6, there's boatloads of these around and the price is good. More abstract choices abound, especially oddball triode-pentodes. Nothing wrong with letting one half of such a device go unused, if you only need one. And hey, you could add a "tube roll" switch (at moderate price increase) to change between the triode and pentode in the envelope!
2. Replace LED with resistor. LEDs cost money.
3. Don't parallel caps: besides being a useless procedure, they waste space. Additionally, don't use name-brand capacitors; end-users know the sellers simply pump up prices artificially on components that have no audible effect whatsoever. I haven't seen many capacitors any cheaper than Cornell-Dubilier DME series, plus, they're really, really compact. Absolutely perfect for coupling use.
4. 6W6 is an oddball choice, but makes a reasonable triode. Prices may vary. 6V6 would be more common, and is in current production [I think..??], but price varies accordingly with market. YMMV. Rolling options include... pretty much any comparable pentode, certainly the 6Y6 mentioned, but also 6K6, 6F6 (a bit lower gain), higher voltage variants like 12L6, and even miniature variants thereof, like 50C5, etc.
5. The output transformer isn't specified, but do make sure to grudgingly spend a couple bucks there, you won't regret it.
6. Dump the series choke, it's expensive dead weight. Yeah it makes things quieter, but the thread title is "Super cheap amplifier" after all!! All right, you probably do want the choke in there, but only grudgingly.
7. We've already got silicon diodes, dump the damper. Also, less filter capacitance could be used, at expense of ripple levels.
Tim
i tend to agree...i use 12W6/12EN6 in guitar pp amps and is preferred over the EL84, i don't know why, but some guitarist like them...
i suspect that in a hi-fi amp, they will sound good....
I would like to see it with a 6Au6 or 6Sj7. A cathode resistor instead of an Led. Loose the choke, keep the damper tube and I don't think it will make it sound tubey but I like the slower warm up. Use a cheap Hammond 125 transformer and loose the paralleled caps. I have some 6W6's in my tube caddy to try.
If you want more cheap, go to silicon amplifier
The russian 6J9P cost U$1 for me. The 6AU6 and 6SJ7 have poor sound.
A led cost cents...if I remove the damper, the choke and the others components, the quality down a lot. Them is best use no power transformer and connect direct to 127V using tubes with 50V FILAMENT.
The hammond 125 is very bad in frequency response...
My friend, you probabily is a silicon amplifier user...
The russian 6J9P cost U$1 for me. The 6AU6 and 6SJ7 have poor sound.
A led cost cents...if I remove the damper, the choke and the others components, the quality down a lot. Them is best use no power transformer and connect direct to 127V using tubes with 50V FILAMENT.
The hammond 125 is very bad in frequency response...
My friend, you probabily is a silicon amplifier user...
The schematic is a prototype...
This schematic is a prototype , not final amplifier.
In a definitive project is correct use a unique capacitor.
This schematic is a prototype , not final amplifier.
In a definitive project is correct use a unique capacitor.
The russian 6J9P cost U$1 for me. The 6AU6 and 6SJ7 have poor sound.
A led cost cents...if I remove the damper, the choke and the others components, the quality down a lot. Them is best use no power transformer and connect direct to 127V using tubes with 50V FILAMENT.
The hammond 125 is very bad in frequency response...
My friend, you probabily is a silicon amplifier user...
The title of your thread is "Super Cheap Triode Amplifier" and your trying to make a silk purse out of a sows ear. The blue Led is not as cheap as a resistor is. Like it was mentioned before there is no need for the choke. The
6Au6 and 6SJ7 when set up correctly do sound good. I don't have a problem with damper tubes but they do not contribute to a tubey sound in my opinion. Your paralled caps are a joke as are your 1n4007 diodes. My suggestion is this... I'f your going to design something put the money into parts that will contribute to the sound but then that takes away from your original title which promises a "Super Cheap Triode Amplifier" Yes, my friend I probably is a silicone amplifier user. A properly designed SS amplifier and a tube amplifier both sound good. The goal in my opinion is to design an amplifier that will reproduce the signal fed into it without adding something that isn't supposed to be there. Just my .02
Don't know about all of you, but in my local tube shop resistors cost 0.25 €, and LED's (all single colours) cost 0.15 €.
Cheap doesn't have to mean bad. You can always go worse in quality by spending less. A couple of cents difference at most to buy a LED is one of the best spent cents as per sound quality in a scheme like presented by OP.
Cheap doesn't have to mean bad. You can always go worse in quality by spending less. A couple of cents difference at most to buy a LED is one of the best spent cents as per sound quality in a scheme like presented by OP.
My friend
You have your opinion and I have mine.
Here in Brazil the blue led is more cheap and the quality is best with your use.
The damper diode do not is necessary, but is a protection for power start up on the signal and power tubes and cost U$1 each in USA...
The choque is for a best filtration...buy probabily this do not is important for you...
I use the E180F because I make a comparation with several small signal pentodes and really sound best in my opinion and cost U$1 in ebay.
But you can remove all this components , use a bad transformer as the hammond 125 and the money is yours !!!
In my project I use the cheap and good Edcor this days...
Is cheap, but have a best frequency response...
Good luck with your trashistor amplifier... I love burn SS amplifiers...is a trash !!!
Aldovan
Yes !!!
Actually I use the 6J9P.
It is superior to Tesla E180F gold pins...
Thanks,
Aldovan
Actually I use the 6J9P.
It is superior to Tesla E180F gold pins...
Thanks,
Aldovan
Great thread Aldovan – don’t worry, he’s from Barcelona
Yes , is true !!!
For me a expensive amplifier use a 300B or equivalent.
This small 25L6GT amplifier play fine, see here:
25L6GT tube in single end mode - YouTube
Fivre 25L6GT in triode mode - YouTube
In the moment I make tests with the excellent 47 in pentode mode:
Raytheon 47 pentode in Single ended mode - YouTube
Raytheon 47 pentode tube in Single Ended Class A - YouTube
Other fine tube, the 6A4:
Class A 6A4 direct heated pentode - YouTube
My 3C24 amplifier:
Utah Full Range - YouTube
3C24 SE class A2 amplifier (red plates) - YouTube
Aldovan
*but in my local tube shop resistors cost 0.25 €, and LED's (all single colours) cost 0.15 €.* ...
wow!!
oh to live in a place with a local tube shop, I thought that would have been restricted to Japan.
how luxurious! AFAIK the last tube radio place in Dublin closed down around the early nineties.
wow!!
oh to live in a place with a local tube shop, I thought that would have been restricted to Japan.
how luxurious! AFAIK the last tube radio place in Dublin closed down around the early nineties.
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