I have a friend who is after building a valve amp, being a relative novice he wants good build info, so layout, chassis dimensions, well documented step by step instructions. SE or PP, about 10-15w +, nothing too expensive, he has a roughly £500 budget.
Apart from the Mullard 5-10 and 5-20 and Dynaco ST70 I can't think of anything, any idea's?
Andy.
Apart from the Mullard 5-10 and 5-20 and Dynaco ST70 I can't think of anything, any idea's?
Andy.
I will offer my own design.
Thoroughly pleasing performance, feeds a nice 17 watts per channel to any speaker system.
Has a proven David Gillespie bias servo system, ultralinear output transformers, and uses common but popular EL84 tubes, biased to last a long time.
The power/output transformers will be the majority of the cost of course, but the end result equals similar amps costing far more.
I've been using this amp since 2006 and it's been incredibly stable and reliable.
A chassis of 12 x 8 x 2 inches should support the amp nicely.
Thoroughly pleasing performance, feeds a nice 17 watts per channel to any speaker system.
Has a proven David Gillespie bias servo system, ultralinear output transformers, and uses common but popular EL84 tubes, biased to last a long time.
The power/output transformers will be the majority of the cost of course, but the end result equals similar amps costing far more.
I've been using this amp since 2006 and it's been incredibly stable and reliable.
A chassis of 12 x 8 x 2 inches should support the amp nicely.
Attachments
Slightly above but a well documented and well regarded 2*17w amp
ST-35 KIT (120 VAC) - Dynakit Parts
As a well-known item it may be sold later if/when needed and expect to
recover or even make profit.
Something very simple suggests to me an EL84 two stage PP design. Plenty here if you search on EL84 amp.
The alternative, and one which many of us have taken, is to buy an existing amp and modify it. This favours a point-to-point design. A Leak Stereo 20 would be perfect but alas they're almost all restored and upwards of £800.
Another way of doing it is to buy a very cheap Chinese EL84 PCB where you already have the layout. Gives a chance to study and understand the circuit. If you buy Morgan Jones "Valve Amplifiers" it will help enormously. Again, a few of us started that way, checking a design against the book. Morgan includes information on an EL84 amp.
The alternative, and one which many of us have taken, is to buy an existing amp and modify it. This favours a point-to-point design. A Leak Stereo 20 would be perfect but alas they're almost all restored and upwards of £800.
Another way of doing it is to buy a very cheap Chinese EL84 PCB where you already have the layout. Gives a chance to study and understand the circuit. If you buy Morgan Jones "Valve Amplifiers" it will help enormously. Again, a few of us started that way, checking a design against the book. Morgan includes information on an EL84 amp.
As the user is in europe, an item already in europe will be much cheaper and
easier.
A kit :
HiFi Stereo Class AB Tube Amplifier Push-Pull Valve Tube Power Amplifier 24W | eBay
This item is in germany, and as UK still trades within EU there is no extra taxes
A ready built :
Dynavox Tube Integrated Amplifier VR-70E II Chrome Tube Amplifier VR-70EII 2 x 40 W | eBay
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That was the kind of amp kit for EL84PP I was looking at. Seems the pcb alone is this one. Extremely cheap!!
12AU7+EL84 (6P14) 10W+10W Push-pull AMP Stereo Amplifier Circuit PCB Board Bare | eBay
12AU7+EL84 (6P14) 10W+10W Push-pull AMP Stereo Amplifier Circuit PCB Board Bare | eBay
Depends a bit whether this is the start of an odyssey - launching an electronics hobby with a focus on valves - or whether it is a means to an end - getting a good performing amplifier with known components.
I was going to write 'a good performing amplifier at a lower price', but I don't believe that is the case these days since the Far Eastern kits are very competitive.
Wouldn't something like the Boyou EL34 amp be a good starting point? All of the hardware for around £200, plus masses of informed builder's notes on this site, and a good base for improvement, if required.
I was going to write 'a good performing amplifier at a lower price', but I don't believe that is the case these days since the Far Eastern kits are very competitive.
Wouldn't something like the Boyou EL34 amp be a good starting point? All of the hardware for around £200, plus masses of informed builder's notes on this site, and a good base for improvement, if required.
Can we see some photos of your amp build ?
I like the layout of it and may want to build or find one all ready made
Boyou EL34 amp is interesting as you say - single ended. That offers a lot of possibilities for changing stuff. Is the power output going to be enough?
You're after a proper kit then. If you Google search "vacuum tube amplifier kit", the first page will give you a decent list of results.
I have had my hands on some of the "kits" available from AliExpress/Amazon, and the instructions, parts, and designs were absolutely terrible. I would stay far, far away from those options.
If he needs 10-15W, then SE is pretty much out of the question in that price range.
The base for my own PP EL84 amp was taken from a vintage Magnavox console stereo amp - the 9304-20 chassis.
I cleaned out the whole chassis, left the power transformer, filter choke, and tube sockets, created an amp that rivals those $1000+ amps.
The result is impressive sonics, and can drive my 4 ohm floor-standing Advents with ease.
Attachments
It's nearly $300 over budget, but the VTA ST-70 amp is really a great sounding amp that's a pretty straight forward kit. Documentation and support are excellent, and the boards are very robust (aka newbie tolerant).
It's easy to recommend in part because it's not my money 😉, but it's also such a great performer that I think is extra money well spent. The VTA is my 7th, and almost certainly my last amp. It was preceded by some pretty respectable amps - stock Dyna ST-70, Distech LS-2, NYAL Moscode 300, and Hafler, DH500 and I feel that the VTA is in a league of its own. Food for thought.
tubes4hifi amplifier KITs page.
It's easy to recommend in part because it's not my money 😉, but it's also such a great performer that I think is extra money well spent. The VTA is my 7th, and almost certainly my last amp. It was preceded by some pretty respectable amps - stock Dyna ST-70, Distech LS-2, NYAL Moscode 300, and Hafler, DH500 and I feel that the VTA is in a league of its own. Food for thought.
tubes4hifi amplifier KITs page.
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Like the original poster I'm in the UK. I can tell you that shipping and import taxes from the USA would account for quite a large sum of money. Taxes have always been added on to goods from the USA. For some reason goods from Asia don't seem to be charged import duty in my experience - can't say why.
So although you guys in the USA have some great products available, in terms of value for the final price paid a much better deal will be the case from the EU or even from Asia.
So although you guys in the USA have some great products available, in terms of value for the final price paid a much better deal will be the case from the EU or even from Asia.
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Strange, it is same here, I buy almost exclusively from Asia to avoid high costs from the US despite the close proximity
Thanks lads, as I said the amp isn't for me but a mate, I too recommended the ST70 as it has very good instructions and several PCB's for the IP & PS.
I also recommended this build - YouTube it having very well explained instructions, this being I think the most important part of any recommendation. Not easy as he only has £500 as a budget.
I also thought of one of Pete Millets amps, as he has PCB's available.
Andy.
I also recommended this build - YouTube it having very well explained instructions, this being I think the most important part of any recommendation. Not easy as he only has £500 as a budget.
I also thought of one of Pete Millets amps, as he has PCB's available.
Andy.
You have to work hard to build a bad EL84/6BQ5 amp. Baby Huey, Red Light District and El Cheapo are well documented on this forum.
We built a Class A Triode variation of El Cheapo (but only 3.2 W) and it is superb. I have the LEDs for the Red Light District, and Baby Huey is really appealing.
I have. awful set of Dyna ST35/SQA35 iron (w 2 power transformers) and the tubes and a nice chassis. Someday…
dave
We built a Class A Triode variation of El Cheapo (but only 3.2 W) and it is superb. I have the LEDs for the Red Light District, and Baby Huey is really appealing.
I have. awful set of Dyna ST35/SQA35 iron (w 2 power transformers) and the tubes and a nice chassis. Someday…
dave
Soldering stuff on a PCB is trivial compared with creating something finished, safe, and for those of us in relationships, presentable.
Therefore a complete kit has a lot to commend it.
If I did not have future projects coming out of my ears, then a cheaper Chinese kit, with a solid and attractive chassis (i.e. improvable), for a couple of hundred bucks, would be perfect.
My first attempt was a Tubelab SPP, housed in an old PA amp chassis. But layout becomes an issue, and metal working, so a ready made chassis saves 70% of the work.
Therefore a complete kit has a lot to commend it.
If I did not have future projects coming out of my ears, then a cheaper Chinese kit, with a solid and attractive chassis (i.e. improvable), for a couple of hundred bucks, would be perfect.
My first attempt was a Tubelab SPP, housed in an old PA amp chassis. But layout becomes an issue, and metal working, so a ready made chassis saves 70% of the work.
https://en.uraltone.com/kits/hi-fi-kits/uraltone-stereo-hifi-pp-el84-v1-1-tube-amp-kit.html
This kit is point-to-point. No PCB. IT's Finnish. You can buy cheaper from China but for future mods, point-to-point will be a great help. Looks like decent transformers too. You'd have to contact them to see if they can do support in English, which seems they do.
Says "Instructions in finnish only ; schematics, layout and bill of materials are multilingual. Email support available in english free of charge."
This kit is point-to-point. No PCB. IT's Finnish. You can buy cheaper from China but for future mods, point-to-point will be a great help. Looks like decent transformers too. You'd have to contact them to see if they can do support in English, which seems they do.
Says "Instructions in finnish only ; schematics, layout and bill of materials are multilingual. Email support available in english free of charge."
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