[wushuliu]

Getting rid of those stinking green caps is the first step!

which ones? There are a lot of green caps on there!

I'd be more cavalier with getting rid of some of those caps but like the lm3886 board, desoldering this kit is a very delicate affair...

[wushuliu]

Actually I would really, really like to see a build of the TK2050 2X100w (4 ohm) Sure amp.

http://cgi.ebay.com/2-100W-4O-TK2050-Class-D-Audio-Amplifier-Board-improved_W0QQitemZ110505566669QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item19baa521cd

The basic mods are simple enough (input caps, inductors, PS caps), it can be powered with a laptop PS and there are many, many happy owners out there in diy land. I'd be curious to hear impressions from folks on this forum.

Oh yeah, and it's only $45 for the amp!

[Niteshade]

I've done one of those TK2050 amp kits and they are indeed very nice! My build was bare bones and plan on doing another, much nicer version.

Some more kits:
http://store.qkits.com/category.cfm/AUDIO?&StartRow=1

These take more time since the components have to mounted on the board. I purchased the 100 watt stereo kit a while ago and have to finish it.

[Niteshade]

All the green electrolytic caps. Every single one of them. They have a tendency to short out & rupture. They're used on computer motherboards and low end video cards.

which ones? There are a lot of green caps on there!

I'd be more cavalier with getting rid of some of those caps but like the lm3886 board, desoldering this kit is a very delicate affair...

[etcarroll]

A class D amp with tubes up front, that does sound interesting.

This looks fun

http://www.hawkaudio.com/amp/HD-702.htm

[JoshK]

would love to see/hear 300b base preamp.   With awesome trannies ofcause. 

Cheers
Mariusz

The key to using a DHT for a preamp, especially the power tubes, is getting the filament power done right.  DC heating is a must.  The chassis has to be heavy and very well dampened/isolated as most DHT are microphonic.  The filament power supply if appropriately using chokes is as large or larger than the B+ PSU. 

I have plans to build a 46 based DHT preamp.  I think a 71A would be better than a 300B.  Also 10Y/801 or 45s would be better IMO too.  Parts costs is pretty high for a DHT preamp, so commercial ones done right cost $$$. 

[Mariusz]

The key to using a DHT for a preamp, especially the power tubes, is getting the filament power done right.  DC heating is a must.  The chassis has to be heavy and very well dampened/isolated as most DHT are microphonic.  The filament power supply if appropriately using chokes is as large or larger than the B+ PSU. 

I have plans to build a 46 based DHT preamp.  I think a 71A would be better than a 300B.  Also 10Y/801 or 45s would be better IMO too.  Parts costs is pretty high for a DHT preamp, so commercial ones done right cost $$$.

You are right Josh,
300b (and other DHT) aren't the quietest or the best choice for preamp application. Keeping the noise down would be my biggest concern.

I believe Audio Space makes one that might be worth looking into. 


Mariusz

[JackD201]

A class D amp with tubes up front, that does sound interesting.

Yeah, Blair does both tubes and class D so I think it would be cool to see what he could do with both in one box.

[Niteshade]

Look at this photo:



I do not advise modifications that have parts hanging off PC boards. It's physically a bad idea. Perhaps it would be better to find different SMT style components if mods are going to be tried.

Another note: I believe someone downgraded one area of this board. I see two blue electrolytic capacitors taking the place of the SMT solid capacitors. Solid capacitors are much,much better.

[wushuliu]

Look at this photo:
I do not advise modifications that have parts hanging off PC boards. It's physically a bad idea. Perhaps it would be better to find different SMT style components if mods are going to be tried.

Another note: I believe someone downgraded one area of this board. I see two blue electrolytic capacitors taking the place of the SMT solid capacitors. Solid capacitors are much,much better.

Sorry I was just looking for an example to show side by side w/ the stock. Can't speak for the actual choices they made...

[Niteshade]

I'm glad you brought up the photo! 

It's very important. There is nothing wrong with doing mods- but you don't want something that's overly delicate and easy to damage.

[wushuliu]

I'm glad you brought up the photo! 

It's very important. There is nothing wrong with doing mods- but you don't want something that's overly delicate and easy to damage.

Like say, using all copper heatsinks on the TK2050 that are prone to fall off? 

[xecluded]

How about a famous Marantz 7C clone:

http://cgi.ebay.com/VACUUM-TUBE-LINE-PREAMP-MODULE-7C-BASED-DESIGN_W0QQitemZ250605175343QQcmdZViewItemQQptZVintage_Electronics_R2?hash=item3a593b822f

[Mariusz]

 Or Jadis.......
I know that plans/boards/kits have been available for years but can not speak what're it's morally correct or not.

If it is, I would like one. 


Mariusz

[Bemopti123]

The Jadis, Matisse, Mac C22 circuit diagrams have been freely and legally available online for years.

I don't think there's any conflicts with these 'bootlegs'.

If so, I will not mention them again.

I think the problem is that although schematics were available for years, it is usually said that commercial applications usually require permission....which is not the case for people who do 1 or 2 copies for their own use or to give away.

The outfits that sell these kits, perhaps might not be breaking the law if they sort of hint at the type of circuit or the amps that they are attempting to imitate, without mentioning names.  The fact that they do so, outright, while illegal, it is not enforceable from the location they are selling their wares from. 

Anyway, people need to live with their conscience when they decide to purchase these items from Ebay.