has there been higher wattage bottlehead amps in the past?

[guf]

what if i wanted to build a 22 or 40 watt amp. where would i look?

 

[Mike B]

Take a look at this;

http://www.dynakitparts.com/dynakit-products/amplifier-kits/ST-70-KIT

No experiance whatsoever.  It's a tube kit.  That's all I know.

 

[Zimmer64]

I have built a ST70 kit from tubes4hifi and I am super happy with it. I think corndog has one too

http://www.tubes4hifi.com/bob.htm

Audionote has a parallel 300b kit that gives you around 20 watts too, but i have no experience with it. Doc B once wrote about runing the paramounts in parallel. That is also an option.

Best

Michael

 

[Zimmer64]

http://www.bottlehead.com/smf/index.php/topic,4777.0.html

 

[Grainger49]

I've been a Bottlehead for about 11 years.  I know of some of the earlier Legacy Products.  I do not remember anything with more power than a 300B, 8WPC.

 

[corndog71]

I used to have an ST70.  I traded it for a pair of speakers.  I currently have a pair of MkIV monoblocks as well as my super ultra mega modified ST35.

Any of the Dynaco kits make for a great and relatively inexpensive tube amp.  The circuits are not much more complex than a Bottlehead kit.  There's lots of room for tweaking of these old amp designs with modern parts.  Just be careful as they operate with higher voltages and can be very dangerous if not handled properly.

My next project will be to build Bob Latino's ST120 in my super ultra mega fashion.  I've been wanting to build a KT88 amp for years. 

 

[Doc B]

We had a design meeting yesterday. As usual this topic came up, as it has for 15 years. I noted that running multiple Paramounts with the secondaries wired in series sounds better than the other options available for that power level. As usual the idea is a very tough sell because it isn't they way everyone else does it and it costs money. My take on this that if you want our product you are probably looking for a certain kind of sound. I would like to deliver that, but when it comes down to it it seems that a lot of people really just want a lot of power for as little expenditure as possible. The single tube single ended options require high voltages that we will not incorporate into a kit. So multiple tubes seems to be the only way to get there. At the end of the discussion we had a vague proposal of doing perhaps parallel single ended using multiple triode wired EL34s. If we can come up with something that is reasonable in size and sonics we will do it. But if all we can make for what people are willing to spend is the same old push pull class AB stuff, I will probably remain resistant.

The other potential option is a stereo SE 300B power amp that could also be used as a series single ended monoblock - you build two for stereo, and each has around 16-18W output. This would pretty much guarantee the sound I would like to achieve, but it would be less efficient in terms of dollars per watt than the multiple EL34 idea.

 

[galyons]

...
The other potential option is a stereo SE 300B power amp that could also be used as a series single ended monoblock - you build two for stereo, and each has around 16-18W output. This would pretty much guarantee the sound I would like to achieve, but it would be less efficient in terms of dollars per watt than the multiple EL34 idea.

This design worked very well in the Golden Tube Audio SE40 with 6L6GGC, (3 per channel).  I have run EL34's in the amp, as well and the sound was sweet.  The EL34/6L6GC/6550 family are great power tubes.  Designing an amp to bias all three in PSE triode would give quite a nice output power range.  Could this be as simple as the changes required on  Paramours to go from 2A3 to 45!?

About 5 years ago I used a SE40 chassis, where the board had been fried, and I point-to-point wired stereo PSE 300B's, 2 per side.  It was a wonderful sounding amp that I wish I had never sold.  I have another board-less chassis to try again.

You guys do wonderful things with the SE designs and parallel feed.  Don't muck the mojo!!!!

Cheers,
Geary

 

[Paul Joppa]

Just to note - our amps have a plate efficiency around 30% (i.e. not counting heater/filament/bias/driver/regulator power) fairly close to the theoretical maximum 50% - so any amp we make will require iron in proportion to the power. So for example an amp with three output tubes of the EL34/300B dissipation class will necessarily weigh nearly as much as three Paramounts, occupy nearly as much real estate, consume nearly as much power from the wall socket, and cost nearly as much.

You might get a cheaper lunch by skipping the dessert, but there ain't no free lunch.