Advice stereo valve amp kit or scratch ?
 

Hi
I've been reading past discussions about building from scratch and I am drawn to the mullard 20w I have a very good selection of components so would only need transfomers & valves but I have been looking at various kits on ebay upto around £250.00 or some built units for the same money or just less.

So question is what do the experts think
Mullard 20w or some design better ( need to source good transformers) ?

Kit on ebay?

Ready built on ebay?

I know most of the ebay route is China made, I do buy stuff from China and never had any problems although I am very selective.

I am going to use it with my 1970's Connoisseur BD1 deck that I have blown the cobwebs off (just ordered some spares for it )

Thanks for your help
regards
Steve

Re: Advice stereo valve amp kit or scratch ?
 

Nothing will beat the satisfaction that you get from your own build. The Mullard 5-20 is a good one to go for.

Make sure you fabricate a good solid chassis and give yourself plenty of room.

Trev

Re: Advice stereo valve amp kit or scratch ?
 

Here is my effort https://www.vintage-radio.net/forum/...ad.php?t=80273 listening to question time through it now. The output transformers where not cheap, I think about £180 the pair a few years ago. These are the most important part of any valve amp, chokes are not needed now as large capacitors are available and new valves for amplifiers are quite inexpensive now. No need for NOS (read expensive) Mullard yellow print valves, that is just an audiophool fad. Mind you building a valve amp just as an amp is also a bit of a money sink. Lots of fun though!

Re: Advice stereo valve amp kit or scratch ?
 

Another plug for me (shame you all cry) is this https://www.vintage-radio.net/forum/...ad.php?t=78559 a bloomin' good amplifier.

Re: Advice stereo valve amp kit or scratch ?
 

I doubt if you can but a kit for the Mullard 5-20 watt Stereo amp for £250?! The 3 transformers will cost more than this.

Re: Advice stereo valve amp kit or scratch ?
 

Cheers Trev
for your reply yes will do a solid job for the chassis with room can't stand installing new consumer units that you have to fight to get the wires in.

Steve

Re: Advice stereo valve amp kit or scratch ?
 

Thanks for the links Merlin

Nice amp layout I like the ceramic valve holders bought some the other week to repair a record player

Hi Edward

I will have to source some secondhand ones if I can.

Regards
Steve

Re: Advice stereo valve amp kit or scratch ?
 

I did a valve amp LOLA some 6-7 years ago that was featured on the forum I obtained the output transformer from Triode electronics (USA) I think I got two of them for about £50
I think to be fair Maplin used to do them for £28 each also
Trev

Re: Advice stereo valve amp kit or scratch ?
 

No question. Build your own. That way you have a free hand to build exactly what you want. It will probably be easier to modify if you need to in the future, and maybe you won't have to use PCBs! Build a nice sturdy metal chassis that looks pleasing to you. You will have a lot of fun in the process and it will sound better because you built it yourself. It will also be unique. I have built a few in my time. I think RS have started selling output transformers again, along with a few valves too.
Alan.

Re: Advice stereo valve amp kit or scratch ?
 

Always build your own!! I started building at about age 8 with a one valve battery wireless. I have never looked back!. Seven years at uni doing electrical engineering, the last 40 years building all sorts of stuff, and its still such a warm feeling when I complete another project. My present amp is home built, just a little 7 watts per channel running into Tannoy monitor golds and its VERY loud. It does lack a bit of power though. A pair of 6BW6 ( 9 pin 6V6's ) running in pentode mode.
The little amp has inbuilt phono stage!! NOT such a good idea, especially as I am using a 6BR7 pentode as the input stage. ( I have small hum problems that Ive not been able to lick)
Second photo is the layout of new amp ;D Pushpull parallel CV428/5B/254M which are loctal 807's so at least 50 watts. My rave is to entice you into your own build, and I wish you well.
DO NOT pooh pooh chinese transformers!! there are some excellent components available at very reasonable prices ( I can give you some websites if thats the way you decide to go)

Cheers
Joe

Re: Advice stereo valve amp kit or scratch ?
 

It depends what you want. If you want a cheap valve amplifier that mostly works buy a Chinese jobbie or better still buy a couple of 5-10 chassis with tfmr's but no valves off ebay and restore them. Transformer's can be got cheaper this way

If you want to learn and build something decent go the home built route, but if you really want a challenge and to learn; design and build your own from scratch. You could start with a simple single ended 3w - ish amp using an ECC83 and EL84 to get your eye in, like the Mullard 3-3. It isn't hard at all and you'll never look back.

Regarding those Chinese ceramic valve holders; I've found some octal ones don't grip the valve pins very well. I found a source of NOS Cinch octal sockets that are far better. Drop me a PM if interested and I'll let you have the link to the ebay seller.

Andy.

Re: Advice stereo valve amp kit or scratch ?
 

Cheers Trev

I will have to check out various suppliers, I need to source all the kit before I move to France.

Regards Steve

Re: Advice stereo valve amp kit or scratch ?
 

Morning Biggles

Yes I get a lot of satisfaction out of building or adapting kit even better when something works first time or I find a fault and fix it

All the best Steve

Re: Advice stereo valve amp kit or scratch ?
 

Hi Andy

I've decided to build from scratch, I have downloaded the Mullard book but I will have to find circuits for a stereo version. Re: valve holders I bought some from Black Magic Amps they hold the valve very snug.

Regards
Steve

Re: Advice stereo valve amp kit or scratch ?
 

Hi Trev, once you decide on the spec let me know as I can probably wind transformers to your design. I may have a suitable mains transformer available

Ed

Re: Advice stereo valve amp kit or scratch ?
 

Very impressive amps Joe, thanks for input, I have been using a soldering iron from an early age I have built test gear from mags 70's 80's all are still working the most bizarre was electronic bagpipes :) I have been adapting electronics for many years but its nice to get back to Valves I suppose it's the nostalgia of past technology coming back to life that's tried and tested and mostly bombproof.
I fondly remember old computer mainframes of the 60's that I operated that to some extent were clunky and solid.

Yes thanks for the offer of suppliers

All the very best
Steve

Re: Advice stereo valve amp kit or scratch ?
 

Hi Ed
Thanks very much for the offer thats very kind of you. I will get the design and layout then I can fabricate the chassis

Regards
Steve

Re: Advice stereo valve amp kit or scratch ?
 

Hi Steve

You seem to have had a much more favourable response than my own Post on the same topic, well done: -

http://www.vintage-radio.net/forum/s...d.php?t=135408

Somewhat bizarrely, I was advised to look in Richer Sounds or Freecycle/Freegle!

I'll be following your progress with some interest - good luck.

Re: Advice stereo valve amp kit or scratch ?
 

There is one post in the thread above that said "it won't be as good as a bought one", of course it can, probably even better. Most people building bought ones are a lot less skilled than you. Time is the manufacturers enemy, it's our friend.

Re: Advice stereo valve amp kit or scratch ?
 

Hi Donald

I read your post and all the answers before posting myself I thought there was some cracking answers it didn't put me off asking my option questions ie ebay kits etc

Regards
Steve