preamp?

[einar]

is it possible to create a simple and cheap but good preamp wich could be added to these great powerstages, here for sale ?
or isnt that interesting?

[dBel84]

I am sure there are many opinions regarding this subject but will share my plans for amp6 for those interested. I have built several variations of the CMoy headphone amp http://www.headwize.com/projects/cmoy2_prj.htm (which uses an opamp to drive the outputs. I use Grado's and have been very happy with the sound (even preferred it to my MF X-can which I got rid of ? ) I stumbled across a pre-amp mod for the MF-A1 which I thought to adjust to use with amp6 as I want an integrated amp which can also drive headphones. http://www.mhennessy1.f9.co.uk/mf_a1/technical.htm#mods The pre-amp will act as a headphone amp ( I added a mute switch on amp6 ) and hopefully the final amp will be a versatile and great sounding amp. I have not yet decided whether to add the buffer stage to the output as outlined by Texas Instruments ... I have yet to build amp6 when it arrives . I will listen more critically when it is all together and modify as time allows. I have not seen whether Autocostruire has released their Heresy tubed pre-amp designed to be partnered with the tripath 2020 chip amps but that looked promising too when i originally looked into the design http://www.audiodigit.com/index.php?section=38
Any thoughts always welcome, especially if you think I am wasting my time. dB

[Gary]

This is an excellent idea providing that the sound quality of any pre matches that of the power kits.
I sometimes find a lack of gain with my tuner and phono stage annoying.
Yes, I know I can change the overall gain of my Amp 3 by changing the appropiate resisters but then there's too much for use of my cd and minidisc players!
i do not want to lose any of the existing sound quality and at the moment am reluctant to consider using a pre, I have tried one that previously I thought was excellent but it quickly coloured the sound.
So, good challenge here for you Jan, how about it?

[plim]

einar,

I'm about to put together a preamp based on the design outlined at http://myweb.tiscali.co.uk/nuukspot/...nclonepre.html, using a stepped attenuator for the volume control (http://www.diyfidelity.com.au/produc...products_id=32).

If you wait a week or two, and the preamp hasn't blown up in my face, I'd be happy to pass you the design and parts selection. And, of course, tell you how it sounds with my amp1b.

[dBel84]

Autocostruire / audiodigit has just released their tubed buffer stage (gain of 1) for 80 euro. They are unfortunately not going to release the tubed preamp but with the high sensitivity of the Tamps, this buffer is a superb compliment. It runs off a 12V dc source and only draws 300mA. ps I am not on their sales team , just thought i would share this info with anyone interested.
http://www.autocostruire.com/catalog...roducts_id=304
dB

[bearman]

On the site that plim sugessted, there is another preamp using single jfets and has PCB board files too and sounds VERY good with an AMP3. Here's the link.

http://myweb.tiscali.co.uk/nuukspot/...clonepre2.html

[bearman]

On the site that plim sugessted, there is another preamp using single jfets and has PCB board files too and sounds VERY good with an AMP3. Here's the link.

http://myweb.tiscali.co.uk/nuukspot/...clonepre2.html

[pairair]

Hi!
I've put together a small and simple preamp that works fine with my AMP5. It uses the Burr-Brown OPA2134 and sounds great as far asI can tell. It's based on the schematics from a Swedish DIY forum:
http://www.naqref.com/pdf/N5mD_schematic.pdf
and the BOM:
http://www.naqref.com/pdf/N5mD_bom.pdf
(the part #'s referres to a Swedish retailer http://elfa.se/)
Here are a few pics of my prototype:
http://pairair.se/N5mD/CRW_2286.jpg
http://pairair.se/N5mD/CRW_2283.jpg
and my (far from optimal) layout:
http://pairair.se/N5mD/Binder1.pdf

/Pär


--------------------------------------------------
Pictures of my project:
http://www.hififorum.nu/forum/topic.asp?TOPIC_ID=50105

[bearman]

Pairair, That little, and I mean tiny, preamp is one of the best I have made. The OPA2134's are tough to find though. I hade to gem ine fron Australia. It would be nice to have those soldering joints a little bigger too. I'm also using +-15v too.

[tobias_svensk]

Here's another one, but it was made from Nagrefs handsketched schematics so the input resistors/caps aren't there yet.
http://www.ettnet.se/~tobias/diy/n5md/