makeing a Tube amp?

[dsavitsk]

Quote:

Originally Posted by bg4533 When going from the tray to a case can you reuse the tube sockets or do you have to get new ones that screw onto the case or something?

If these were "real tubes", I would mount them on top of the case. But these are tiny and put out almost no heat, so I am putting them inside.

 

[andjules]

I'm not sure how far along PPL is, but he is supposedly preparing to release a DIY headphone tube amp design, and it has received a lot of attention from the community here. check out this thread

 

[aeriyn]

I'm thinking about building a Pete Millet Hybrid...

It looks easy enough... but maybe after my successful PIMETA build, I'm getting delusions of grandeur...

Is there a basic parts list for the Millet tubeamp anywhere? $150 for a tube amp sounds too tempting to pass up. =P

 

[etherz]

Bottlehead.com has some sweet kits you can build...Great sounding, good reviews. I ordered the fourplay pre-amp and paramour amps kits...takes forever to ship...there backlog'd like 5 wks.

 

[Kenny12]

well what i'm looking for really is just something that i can do p2p wireing, sounds decent and costs ~100 to make, out of all the projects suggested here what would be the most suitable?

 

[bg4533]

Quote:

Originally Posted by aeriyn I'm thinking about building a Pete Millet Hybrid... It looks easy enough... but maybe after my successful PIMETA build, I'm getting delusions of grandeur... Is there a basic parts list for the Millet tubeamp anywhere? $150 for a tube amp sounds too tempting to pass up. =P

Pete has a BOM here: Link

Kenny12, the Millett schematic looks like it wouldn't be that hard to wire yourself. Skipping the board will keep the cost down a bit.

 

[pho_boi]

has anyone built the amp from http://boozhoundlabs.com/howto/ ? Would it sound better than the S5 Electronics K-12M Tube Amp? Because I am deciding between those 2 to build. For the S5 Electronics K-12M Tube Amp, i will not be buying the kit but just building it from the schematic. Both are easy to build, but the boozhoundlabs one requires less parts.

 

[AndrewFischer]

Quote:

Originally Posted by pho_boi has anyone built the amp from http://boozhoundlabs.com/howto/ ? Would it sound better than the S5 Electronics K-12M Tube Amp? Because I am deciding between those 2 to build. For the S5 Electronics K-12M Tube Amp, i will not be buying the kit but just building it from the schematic. Both are easy to build, but the boozhoundlabs one requires less parts.

I took a quick look at the boozhound design. A 6v6 tube singled ended with no negative feed back will give high distortion.

 

[Wodgy]

Quote:

Originally Posted by AndrewFischer I took a quick look at the boozhound design. A 6v6 tube singled ended with no negative feed back will give high distortion.

It's running triode strapped, so this isn't a problem as long as you don't need a lot of power. Looking at the 6V6 data sheets, distortion is <5% at 1.65W total output. Respectable for a flea powered SET.

 

[Wodgy]

Quote:

Originally Posted by pho_boi has anyone built the amp from http://boozhoundlabs.com/howto/ ? Would it sound better than the S5 Electronics K-12M Tube Amp? Because I am deciding between those 2 to build. For the S5 Electronics K-12M Tube Amp, i will not be buying the kit but just building it from the schematic. Both are easy to build, but the boozhoundlabs one requires less parts.

Good idea on just building from the schematic if shipping costs are a problem.

The S5 kit is a push-pull pentode design rated at 8 watts. The Boozhound project is a single ended triode design rated at just over 1.5 watts. They'll sound different. Tube purists love the SET sound, but if you're trying to drive average speakers the S5 amp is a better choice. If you're listening to speakers up close, say at your computer, you can probably get away with the lower powered amp, and I'd probably recommend that. Note that the Boozhound design is just a generic SET amp. I suggested it because it has a particularly good write-up aimed at beginners, but if you read through it and get a basic understanding of it, the ideas are applicable to pretty much any simple SET design. You can substitute in different tubes or try any design you find on the web.

 

[AndrewFischer]

Quote:

Originally Posted by Wodgy It's running triode strapped, so this isn't a problem as long as you don't need a lot of power. Looking at the 6V6 data sheets, distortion is <5% at 1.65W total output. Respectable for a flea powered SET.

Yup. I spent a little more time looking at the article.

Overall that is a good article. It is a good introduction to tube amplifer design and the resulting amp is worth building for the experience. I don't think it would be something I'd build as my main listening amp. I certainly could recommend building it, playimg with it and then recycle the parts into something better.

Tridode mode will help with disortion but < 5% is still too high for me. There are those that like listening to tube distortion. I'm not one of them.


The sound will be sensitve to the two capacitors in the signal path. The suggested .1uF orange drop is a good choice to stay in budget and would sound ok. I'm not so sure about the 100uF cap on the cathode of the 6SN7. The spec'ed cap will work, but doesn't look very good for audio. I'd pick something else.



The Hammond 125ESE is not a great impedance match for headphones. With the 5000 ohm design load the 125ese matches to 4, 8 and 16 ohm loads. Re do the load line for 10000 ohms and the 125ese will match 32 ohm Grados.

 

[Wodgy]

Quote:

Originally Posted by AndrewFischer Tridode mode will help with disortion but < 5% is still too high for me. There are those that like listening to tube distortion. I'm not one of them.

I'm fine with that in a triode design, since most of that is second harmonic, and I can't hear second harmonic distortion in the neighborhood 8% at all (most people can't; there are some great sound files to test this out for yourself floating around).

Quote:

The sound will be sensitve to the two capacitors in the signal path. The suggested .1uF orange drop is a good choice to stay in budget and would sound ok. I'm not so sure about the 100uF cap on the cathode of the 6SN7. The spec'ed cap will work, but doesn't look very good for audio. I'd pick something else.

This is a budget design, so IMHO there's no need to get picky about cap selection. Paralleling the 100uF cathode cap with a 1uF film is a nice cheap solution for people who are bothered by electrolytics.

Quote:

The Hammond 125ESE is not a great impedance match for headphones. With the 5000 ohm design load the 125ese matches to 4, 8 and 16 ohm loads. Re do the load line for 10000 ohms and the 125ese will match 32 ohm Grados.

You're right, though I think pho_boi wants to run this with speakers. People who want a tube headphone amp would probably be better off building a Millett Hybrid or a Morgan Jones/Singlepower clone.

 

[pho_boi]

thanks for the replies guys

. Now wish me luck in finding a transformer that has a 240v input and output of 12v for the heaters and 175v that gets rectified for the tubes

i think i am right abuot the output, im not sure

 

[AndrewFischer]

Quote:

Originally Posted by pho_boi thanks for the replies guys . Now wish me luck in finding a transformer that has a 240v input and output of 12v for the heaters and 175v that gets rectified for the tubes i think i am right abuot the output, im not sure

240V? No problem.

Which amp are you bulding? Which tubes are you using? If you build the boozhound amp as shown you need 5v, 6.3v, and 275VCT. A Hammond 370HX will work.

Are you using tube full wave or silicon bridge rectifiers?

For 175 and 12 it may be cheaper to go with a pair of transformers. There are transformers in the Hammond 182 and 186 series that would work. You might also find a transformer intended for radio repair, but most of them have 6.3v winding not 12.

Sowter http://www.sowter.co.uk/ has a wide selection and will make just about anything as a custom, but they are a little pricey.