DIY Audio Projects Forum

Hi All, with a couple of kit builds under my belt, Ive decided its time to compliment my system with a nice Valve Preamp. As I am quite the novice on the design/schematic side of electronics I will probably base it on an of the shelf PCB (Jadis JP200 or similar) http://www.ebay.com.au/itm/Tube-PreAmp- ... 45ffd2c7c4 with valve baxandall tone control and all the other goodies I can fit into it, but populate the boards with quality components.

My question is around peoples opinions and experience of resistors, capacitors and valves. I believe metal film resistors are the quietest? though is there a difference in quality between brands (Dale, Allen Bradley or any others you know of)?, and I guess my question is the same for Caps and Valves, I pretty much have my heart set on Mundorf Caps and Mullard valves, but dont want to jump in both feet without doing some study first!

I'm open for any suggestions opinions you wish to throw out there, My construction suggestion is by no means set in stone, and if someone has an idea that might better suit me, I would certainly be interested in hearing about it.

Cheers guys, anything is apprecitated!

Ox

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If it can't be fixed with Gaffa Tape, It can't be fixed!

Hi, Your choices of resistors and caps are fine. As for which are quieter carbon film or metal film...to me much of a toss up. They do tend to sound a tiny bit different and the carbon ones a little smoother, the metals a little crisper. Not much and other things will have a far greater effect. As for tubes.... Having just designed and built (three now) all valve phono preamps I have some thoughts on that. I now use JJ Gold Pin ECC83S for high gain circuits. I tried all the common ones and they were the quietest. The supposed to be quiet new production Mullards were more than 2 db noisier than the JJs. I sent 10 back to the supplier. EH were in between, but not the quietest. Most others were worse. There are likely other quiet tubes out there but with a signal to noise of -90 dbv on the preamps, I'm not going to hunt them out. I like to use Auricaps and Jantzen Silver Z caps in my preamps... a matter of taste as I like how they sound. As I said at the beginning, your choices should be fine. I tend to use KOA Speer resistors and some Dales. A hint... use good sockets. Often pretty ones with "gold " pins are not as good as less gaudy others. I use Beltons.

Good luck with the project and let us know how it works out

Good listening
Bruce

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Some of my DIY Tube Amplifier Projects:

• PoddWatt: 5751 / EL84 Push-Pull DIY Tube Amplifier Project
• OddBlocks: KT88 Push-Pull DIY Tube Amplifiers (Mono Blocks)
• ForeWatt: ECC802S (12AU7 / ECC82) DIY Tube Preamplifier Project
• GrooveWatt: Tube (Valve) RIAA Phono Preamplifier Project

Thanks Gofar, your reply has been a great help of experience, particularly around the valves, I will definately now be going for the JJ golds! I forgot to mention the valve sockets, thanks for passing on that info also. Due to money and time constraints, and the fact I am just finishing up a Sub amp/controller, this will be a WIP, and is going to take me quite some time to collect all the components to make this a reality, but I will definetely be recording it on the forum as it happens. Thank you for you interest!

I would still love to hear anyone elses experiences/knowledges in this area.

Sorry for posting what appears to be a flogged out or somewhat boring subject, I just thought it might be a good idea to try and capture it all in one thread for future newbies and to have all the knowledge in one place.

best regards all
Ox

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If it can't be fixed with Gaffa Tape, It can't be fixed!

Hi All,

I see all of the chinese sort of stuff on ebay is boasting "Wima" capacitors, has anyone here had experience of them, and what are everyones thoughts on them? Do they stack up to the likes of the Mundorfs, Elnas etc?

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If it can't be fixed with Gaffa Tape, It can't be fixed!

Hi Ox,
Other good metal film resistor brands: Holco and Caddock. Riken makes nice carbon composite resistors.

Wima is a good brand and very reasonably priced. However, I would suggest purchasing them from a known source as there are counterfeits floating around.

For new production 12ax7 I like the plain JJ ECC803s and it's a couple bucks less thank new production Mullard tubes.
Cheers

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[ DIY Mains AC Power Cable Cord ] - [ K-12 Tube Amp Kit ] - [ Tang Band D4-1 Horn Speaker Kit ] - [ Monoblock Push-Pull KT88 Tube Amp Kit ]

I would add to be very, very cautious of any "high end" quality product being sold from China on ebay. WIMA brand is German and not made outside of the EU. China has no regard for national/international trade mark, patent or copyright and many counterfeits come out of China. Not saying everything from China is illegitimate. Even though crap, a lot of outsourced product does come from there. You should be careful, none the less. ebay seems to be their "playground".

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The key to a successful build is to keep the smoke IN the circuit.
-Les

Science without religion is lame, religion without science is blind. - Albert Einstien
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LM380 Bridged Guitar Amp, Oatley K301 Phono Pre-amp, Oatley K272 Headphone Amp, Tube proto-board
Current project: 6V6 "pseudo Champ" prototype
Still to come (On hold): 6CG7/12AX7 Guitar amp (modified FireFly)

You guys are awesome! THANK YOU!, I really appreciate what your saying "Les", and thats the type of information I'm looking for, Thank you both Gio and Gofar, for your advice/opinions on valves and sockets!

Without trying to put anyones nose out of joint (Aussie saying for dont upset!!!) is there anyone else with anything to add?? Lets make this thread a value

Cheers
Ox

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If it can't be fixed with Gaffa Tape, It can't be fixed!