I need 3-5W tube amp, something similar to this: Amazon.com: Gemtune APPJ PA1501A mini tube amplifier with 6AD10 tube (black): Electronics Is there any DIY project or kit available?
Thanks in advance!
Thanks in advance!
rpi,
Happy New Year!
For a "project" you can take a look at the Tubelab SSE:
Tubelab SSE | Tubelab
A good beginners project, but not a "kit". You will need to source the parts (transformers, tubes, components) by yourself. However, plenty of information on the Tubelab website, and the forum members (Tubelab has a sub-forum on diyA) are generally pretty helpful too.
However, the amp will not be as compact or low cost as the one that you linked.
Another DIY project that I can recall that was both compact and easy to do, is the Parks Audio Budgie SE; but as far as I know, Shannon has discontinued the PCB.
A word of caution - with tube amplifiers you will be dealing with high voltages (which are lethal)
Happy New Year!
For a "project" you can take a look at the Tubelab SSE:
Tubelab SSE | Tubelab
A good beginners project, but not a "kit". You will need to source the parts (transformers, tubes, components) by yourself. However, plenty of information on the Tubelab website, and the forum members (Tubelab has a sub-forum on diyA) are generally pretty helpful too.
However, the amp will not be as compact or low cost as the one that you linked.
Another DIY project that I can recall that was both compact and easy to do, is the Parks Audio Budgie SE; but as far as I know, Shannon has discontinued the PCB.
A word of caution - with tube amplifiers you will be dealing with high voltages (which are lethal)
Lots of complete kits on eBay from China. Chassis, transformers, tubes everything.
Search for 6P3P amplifier kit, or EL34 amplifier kit.
Most have a thread on here to help. Boyuu A9 or A10 for example.
In the States there must be a good choice too?
Heed the high voltage warning if you have little or no experience of tube/valve amplifiers.
If you are comfortable with tube circuits it might be an idea to look at old Magnavox console amplifiers and 'do one up'. 8802 and 9302 are popular.
Search for 6P3P amplifier kit, or EL34 amplifier kit.
Most have a thread on here to help. Boyuu A9 or A10 for example.
In the States there must be a good choice too?
Heed the high voltage warning if you have little or no experience of tube/valve amplifiers.
If you are comfortable with tube circuits it might be an idea to look at old Magnavox console amplifiers and 'do one up'. 8802 and 9302 are popular.
If you want a tiny and inexpensive amplifier such as the 6by6 inches APPJ you referenced, a switched mode high voltage power supply is needed to avoid the power transformer. To my knowledge, there is no commercial kit available yet with this feature; there is another APPJ board with a FU32 tube and a SMPS but it is almost twice the size.
The smallest and cheapest full tube amplifier kit from China I've found has 6F3 tubes with a 7by8 inches chassis. If drilling a few holes in an alluminium chassis is not a issue for you, I suggest to build it with locally sourced parts at about the same price (and you may use better transformers). It is very simple, it is similar to the mini amplifier published on the january 1963 issue of electronics illustrated at page 82, check the american radio history website to download the issue.
The smallest and cheapest full tube amplifier kit from China I've found has 6F3 tubes with a 7by8 inches chassis. If drilling a few holes in an alluminium chassis is not a issue for you, I suggest to build it with locally sourced parts at about the same price (and you may use better transformers). It is very simple, it is similar to the mini amplifier published on the january 1963 issue of electronics illustrated at page 82, check the american radio history website to download the issue.
You have the bottlehead Stereomour II kit with an 2A3 tube in SET config giving 3.5W output. I never used it, but it's highly rated i hear. But it's not cheap at all:
Stereomour II Stereo Single Ended Integrated 2A3 Amp | Bottlehead
Stereomour II Stereo Single Ended Integrated 2A3 Amp | Bottlehead
5 W. out of the power pentode section of the 6AD10 compactron is about right. However, I dislike pentode voltage amplifier into pentode "final". I fear bludgeoning the setup with NFB will be needed to deal with highly irritating IM distortion.
Let's see if we can come up with a price competitive setup using a triode voltage amplifier and power pentode. The most expensive parts in a tube amp are the magnetics. Edcor's GXSE15-5K O/P "iron" costs $43.37 and 2 (1/channel) are needed. "Full wave" voltage doubling (Schematic provided) a $15.81 Triad N-68X isolation trafo takes care of B+. A $13.92 Triad VPS24-1000 takes care of heater power. That totals less than $125.
With a roughly $200 budget, I think we can better that Chinese amp's performance. We can't match the fancy case work, but my preference is sound over looks. Corners have to be cut somewhere at this price point.
Sockets set up for the Russian 6Π15Π-EB (6p15p-ev) also accept EL84s. Approx. $20 buys 4 tubes off ebone.
I'm thinking 12AX7 section voltage amplifier and full pentode mode "final". A nice added touch would be 0A2 regulated g2 B+. I don't like asking the 'X7 triode to drive the CMiller of UL mode O/P tube.
Let's see if we can come up with a price competitive setup using a triode voltage amplifier and power pentode. The most expensive parts in a tube amp are the magnetics. Edcor's GXSE15-5K O/P "iron" costs $43.37 and 2 (1/channel) are needed. "Full wave" voltage doubling (Schematic provided) a $15.81 Triad N-68X isolation trafo takes care of B+. A $13.92 Triad VPS24-1000 takes care of heater power. That totals less than $125.
With a roughly $200 budget, I think we can better that Chinese amp's performance. We can't match the fancy case work, but my preference is sound over looks. Corners have to be cut somewhere at this price point.
Sockets set up for the Russian 6Π15Π-EB (6p15p-ev) also accept EL84s. Approx. $20 buys 4 tubes off ebone.
I'm thinking 12AX7 section voltage amplifier and full pentode mode "final". A nice added touch would be 0A2 regulated g2 B+. I don't like asking the 'X7 triode to drive the CMiller of UL mode O/P tube.
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Uh, I assume if that's what he wanted he would have asked there? He does specifically state "tube" in his post...
I can definitely recommend the TubeLab SSE, very nice and versatile design. I'm working on a PCB design for a small SE amp as well, using EL84 and similar tubes. 3-5 watts would make a UL or pentode connected EL84 or EL86 a good option.
I can definitely recommend the TubeLab SSE, very nice and versatile design. I'm working on a PCB design for a small SE amp as well, using EL84 and similar tubes. 3-5 watts would make a UL or pentode connected EL84 or EL86 a good option.
Thanks a lot for different options! I should probably give more info to clarify the requirements.I 'm thinking about new model of the Peppy player:
Home * project-owner/PeppyPlayers.doc Wiki * GitHub
This time I'd like to make steampunk model. Here is the preliminary sketch:
That colorful stuff will be VU Meter based on Nixie tubes IN-9:
Serial VU Meter * project-owner/PeppyMeter.doc Wiki * GitHub
I thought that adding a tube amp would make the player look more steampunk
Hence the requirements - low wattage as this is boombox and preferably small size as the space is limited.
The tubes could be placed on top of the player. And another crazy idea was to lift the board with tubes by means of stepper motor. So that the tubes would magically appear on top after the player startup
Probably the easiest approach would be to buy the amp which I referenced, disassemble, rewire and mount in the case/enclosure. It's just difficult to break the amp which costs almost $200 Though that's probably the easiest way.
Home * project-owner/PeppyPlayers.doc Wiki * GitHub
This time I'd like to make steampunk model. Here is the preliminary sketch:
That colorful stuff will be VU Meter based on Nixie tubes IN-9:
Serial VU Meter * project-owner/PeppyMeter.doc Wiki * GitHub
I thought that adding a tube amp would make the player look more steampunk
Hence the requirements - low wattage as this is boombox and preferably small size as the space is limited.
The tubes could be placed on top of the player. And another crazy idea was to lift the board with tubes by means of stepper motor. So that the tubes would magically appear on top after the player startup
Probably the easiest approach would be to buy the amp which I referenced, disassemble, rewire and mount in the case/enclosure. It's just difficult to break the amp which costs almost $200
Though that's probably the easiest way.
Have a look at the Mullard 3-3 - Mullard 3-3. Three Watt Amplifier which gives concise instructions, layout etc. The ampt has excellent performance and is simple to build. Local feedback ensures excellent bandwidth.
VVT transformers do transformer "kits" see - http://www.vvttransformers.co.uk/valve_tx_sets.htm which are reasonably priced and good quality.
Andy.
VVT transformers do transformer "kits" see - http://www.vvttransformers.co.uk/valve_tx_sets.htm which are reasonably priced and good quality.
Andy.
Thank you! Unfortunately the kits for Mullard 3-3 are not available on VVT site. The one which I found on e-bay:
Mullard 3-3 Magnetics kit | eBay
costs the same as the whole amp which I referenced.
Mullard 3-3 Magnetics kit | eBay
costs the same as the whole amp which I referenced.
Nice project! Having a real tube amplifier instead of a fake one is surely a big advantage for the sound quality, if you use a high quality, high efficiency speaker. Tubes become hot, do not put any heat sensitive device near them. If you need to use plastic parts, use a sheet of metal as heat shield.
You are also looking for something that glows: I suggest a 6E5P "spud" amplifier. The cathode of this tube is exposed, so you will see it glow when the amplifier is turned on. The enclosed picture is my build of the schematic described here: Spud Amplifier with 6E5P Tube. It works and sounds really well, power output is lower than your requirements but it does not matter if you have a high efficiency speaker.
If you still want to buy the ready-made 6AD10 appj tube amp, be aware of the drawbacks. The output transformers are tiny and low frequency response is not good. I attach the picture of the inside of the transformer cover of the EL84 version of this amplifier, I believe it is the same on the 6AD10 version. As you easily see, the output transformer has the same size of those found in the kitchen radios from the '60 (but high frequency response is better on this modern part). For $200, you may get much better quality elsewere.
The 6AD10 tube is a standard one and therefore only the top and bottom part of the glowing cathode are visible. On most China sourced amplifiers there is a big red LED underneath the tube to light it up, but it looks fake to me.
You are also looking for something that glows: I suggest a 6E5P "spud" amplifier. The cathode of this tube is exposed, so you will see it glow when the amplifier is turned on. The enclosed picture is my build of the schematic described here: Spud Amplifier with 6E5P Tube. It works and sounds really well, power output is lower than your requirements but it does not matter if you have a high efficiency speaker.
If you still want to buy the ready-made 6AD10 appj tube amp, be aware of the drawbacks. The output transformers are tiny and low frequency response is not good. I attach the picture of the inside of the transformer cover of the EL84 version of this amplifier, I believe it is the same on the 6AD10 version. As you easily see, the output transformer has the same size of those found in the kitchen radios from the '60 (but high frequency response is better on this modern part). For $200, you may get much better quality elsewere.
The 6AD10 tube is a standard one and therefore only the top and bottom part of the glowing cathode are visible. On most China sourced amplifiers there is a big red LED underneath the tube to light it up, but it looks fake to me.
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Thank you pcan! That's probably what I need. The wattage is lower then I expected but hopefully I can find small efficient speakers.
The size of transformers is a bit on a large side but I hope that at least the one for the power supply I could keep outside of the enclosure.
I'm not sure which current is flowing in that amp. Could you give me the wattage of the resistors used in the amp?
Is it better to buy a matched pair of the tubes or it doesn't matter for this amp?
How long the pair of tubes can serve if I will use the amp let's say about 2 hours a day? I'm just wondering how many pairs I have to buy.
There is the question in that thread about transformer which could be used in US for that amp: Spud Amplifier with 6E5P Tube
Is Edcor XPWR058 suitable or not? EDCOR - XPWR058
Thanks a lot!
The size of transformers is a bit on a large side but I hope that at least the one for the power supply I could keep outside of the enclosure.
I'm not sure which current is flowing in that amp. Could you give me the wattage of the resistors used in the amp?
Is it better to buy a matched pair of the tubes or it doesn't matter for this amp?
How long the pair of tubes can serve if I will use the amp let's say about 2 hours a day? I'm just wondering how many pairs I have to buy.
There is the question in that thread about transformer which could be used in US for that amp: Spud Amplifier with 6E5P Tube
Is Edcor XPWR058 suitable or not? EDCOR - XPWR058
Thanks a lot!
Caution,
There is a thread on this site regarding the Mullard 3-3 amplifier. It can have problems with various EF86 tubes. The DC voltages and currents of the input and output tubes can be "just about anywhere they want to be". Just my opinion, and something one of the recent builders observed. Also, be careful of using negative feedback with transformers that may not match the original transformers for gain / phase characteristics, unless you are prepared to adjust the feedback components, and have proper test equipment to do so properly.
Maybe the kit has transformers that are close enough. But you may need to select EF86 tubes, and they are expensive.
There is a thread on this site regarding the Mullard 3-3 amplifier. It can have problems with various EF86 tubes. The DC voltages and currents of the input and output tubes can be "just about anywhere they want to be". Just my opinion, and something one of the recent builders observed. Also, be careful of using negative feedback with transformers that may not match the original transformers for gain / phase characteristics, unless you are prepared to adjust the feedback components, and have proper test equipment to do so properly.
Maybe the kit has transformers that are close enough. But you may need to select EF86 tubes, and they are expensive.
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SE pentode pretty much SUX. From the spec sheet, THD= 10%. YUCK!. Also, let us not forget that the 6AD10 small signal section really isn't a pentode: it's a quadrature FM demod tube as the type was intended for the audio strip of TV sets, and sonic performance wasn't a consideration. I wouldn't go that route.
From the data sheet, I was thinking gated beam detector. Thanks for confirming my suspicion.
The OP stated a "steampunk" look is desired. That makes me repeat the 0A2 regulated g2 B+ suggestion. Gas discharge regulator tubes glow with pretty colors. Look here. The color of the suggested 0A2 is similar, but it is a physically small 7 pin mini type, which is well suited to a "boombox".
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