my 300B SET project

[dnewma04]

Good to know. I know when I chatted with him and mentioned that I'd probably make audiophiles hate me for going with a PP 300B amp, he surprised me by saying he'd not consider using a 300B any other way. The Amityville amp was the specific amp he mentioned as the best 300B amp he had ever heard.

 

[TerryO]

Good to know. I know when I chatted with him and mentioned that I'd probably make audiophiles hate me for going with a PP 300B amp, he surprised me by saying he'd not consider using a 300B any other way. The Amityville amp was the specific amp he mentioned as the best 300B amp he had ever heard.

I know that Bud thinks the 300B is just about as good as it gets when it comes to triodes. I like the sound of the 2A3 and especially the 45, but that's just me...tin ear and all! With your Unity Horns you have the decided advantage of being able to use just about any tube you want.

At our recent diy meet, Rene' Yeager brought a 300B push-pull Class A amp with O'Netic output iron that sounded pretty nice. He used some sort of outboard precision power supply with it, but I never had a chance to ask him about it.

Best regards,
TerryO

 

[dnewma04]

I've got a little 45 SET amp here that I may use on the compression drivers. Perhaps the 300B PP on the mids and 200ASC Icepower amps on the bass.

 

[Dave C]

TerriO, Send him this thread, I would certainly be interested in more information and some pictures of his OPTs.

 

[TerryO]

I've got a little 45 SET amp here that I may use on the compression drivers. Perhaps the 300B PP on the mids and 200ASC Icepower amps on the bass.

Dave,

With that setup you can turn the knob up to deaf and a half!

(IOW: Just enough.)


Best Regards,
Terry

 

[TerryO]

TerriO, Send him this thread, I would certainly be interested in more information and some pictures of his OPTs.

Dave,

I'll try to do it tomorrow, although I can't guarantee anything.
(Update: I sent him an email a few minutes ago)

Best Regards,
TerryO

 

[BudP]

Hi everyone, Terry tells me I am the subject of conversation and lo and behold I find lots of .....imprecise comments. Don't get me wrong, all publicity is good publicity....

Any way, yes I do build SE output transformers. I have built them for 300 B, 45, 2A3 (some being readied for Island Pink right now) 10, GM70 and if I dug around, probably some others. There have also been a number of beam tetrodes and pentodes, with ultralinear taps, in SE mode too.

I built the outputs for Wright Sounds model 7 amplifier and still do make them. They are not an ultrafi product, seeing as they had commercial concerns foremost. I do make three core sizes for SE OPT's and they range in price from $120 ea for those found in the Model 7 to $640 each for level three SE OPT's in a very large core size. I can provide data sheets for anyone who is interested. I have pulled load lines for a large number of tubes, looking for an optimum linearity. For the 300 B that occurs at 4.545 Kz and for the 2A3 at 3.0 Kz. Again these are also available if there is interest.

As for preferring PP to SE, no. I do like the AudioPrism Debut amp I have, or I wouldn't have it. I have had a number of SE amps and liked them too. The most current personal plan has a SE 300 B amp driving a Lowther PM6A 16 ohm silver voice coil that has been treated to EnABL 2.0 levels. These will be mounted in a no baffle configuration, nude and omni and Jon Ver Halen can comment on what Lowthers treated to EnABL 1.0 sound like.

One of the characteristics that has always bothered me with 300 B SE amps is the driver stage. Noise of one sort or another seems endemic, at least with my skill levels. So, I have asked Gary Pimm and Rene' Jaeger (Berkley Audio Dac, Pacific Microsonics, HDCD inventor) to help. Their recommendation is high voltage lateral Fets, some new version just out, run in push pull and used to drive the 300B in SE mode through a 1+1 to 1 nickle core interstage. I have Rene's turnaround of that notion here and it is definitely a SE 300 B amplifier sound, even though the 300 B is used in a completely disconcerting place in the circuit.

Easily the most elegant sounding amp I have ever heard and I hope he makes it available in commercial form. And the most surprising part, no high order IM distortion, to fatigue your ears with something you cannot even hear. No noise at all and effortless dynamics. And, that magical 300 B way with the beauty of music is blatantly obvious. By the way, it also uses a PP OPT meant for Lynn Olson's Karna and Amity amplifiers, with a 6.6 kZ load line no less.

So, if you want high performance SE OPT's, I can build them for you, but so can Dave Slagle, Per Lundahl and Pieter Truffant of Tribute Audio. We are all at about the same level of performance and cost. Each of us has his particular emphasis to offer a discerning listener, with mine being amazing amounts of internal gradient structure information, for tone and transients.

Bud

 

[dnewma04]

Sorry for misinterpreting your comments Bud. When you led me towards PP 300Bs, I was pretty sure you preferred the performance of them.

 

[SET12]

Sorry for misinterpreting your comments Bud. When you led me towards PP 300Bs, I was pretty sure you preferred the performance of them.

Regardless dnewma04, You just opened the door for some us to Buds work, nothing to feel bad about! Great designers are hard to come by! Especially for people like myself that are capable of scratch designing.

If it weren't for your comments I wouldn't of known of Buds work.

Thanks dnewma04

SET12

 

[BudP]

dnewma04

Not sure you misinterpreted them.

I do think that the Amity amp from Lynn is one of the best sounding amplifiers ever. That it uses 300 B tubes is only one of the reasons. The power supply rejection, isolation of the two stages with an interstage transformer and robust power supplies are also contributing factors.

I do not particularly like the Karna, his three stage amplifier. No doubt that it has considerably more refined performance. To my ears that refinement comes as an analytical depth of information rather than a musical portrayal of information. Much the same thing as is found with toroidal OPT's. Not a bad thing, just not to my taste.

Single Ended amps can have just as many or more failings, with insufficient driver section current swing ability sitting right at the forefront. In 300 B SE amps lack of a true CCS to support both the driver and 300 B tube is another problem area and another is use of driver tubes that don't match the 300 B sonic character.

So, my opinions on amps are pretty complex and when I am designing OPT's IT's or input transformers I do try to ask enough questions to get an understanding of what my potential customer is after and what their experience level is. I have no problem recommending Edcor transformers to someone who is beginning a design series. No reason to spend your money on expensive iron until you have solved all of the problems Edcor iron can display for you, and their products performance requires no apologies. When you get into refinement of texture, depth of information transform and grace under pressure, is when you want to purchase transformers from me or my esteemed competition.

Bud

 

[TerryO]

dnewma04

Not sure you misinterpreted them.

I do think that the Amity amp from Lynn is one of the best sounding amplifiers ever. That it uses 300 B tubes is only one of the reasons. The power supply rejection, isolation of the two stages with an interstage transformer and robust power supplies are also contributing factors.

~~~~~~~~~~~~~~~~~~snip~~~~~~~~~~~~~~~~~~~

Bud

I wrote a response to Bud's first reply earlier today, that evidently just got dumped into the cosmos and probably ended up being read by Elvis.
The Amity amp is a superb amp and for those that like the sound of the
300B, but need a bit more juice, it's a nearly ideal solution that doesn't, IMHO, give up very much to a 300B SET.
:thmbsp:

I believe that Bud, like myself, has had to do a bit of rethinking since Rene' Yeager built his 300B based amp late last year.
If all amps sound alike...then that's the amp they should all sound like!

Best Regards,
Terry

 

[Dave C]

BudP, I want to thank you for joining the group and this thread that I started a few years telling about my 300B build. I was fortunate back then to have met SET12, I had the idea of using the 7193 tubes as drivers for the 300B. I wanted a SS power supply and Dan helped me with that and getting the 7193 tubes to work. I think Dan would like to see me make a few changes to my driver section but I am very satisfied with it. I have Hammond transformers now and would like to upgrade them. Rather than deal with middle range stuff I figured I'd clime to the top of the OPT area. I originally had the idea of using Plitron OPTs but never bought them, the Hammonds sound OK. I'm driving Klipsch RF-25 speakers with scratch built cross overs that use North Creek inductors and Mundorf caps. They are perfect for my ears. I'm looking for more soundstage, I've got good depth but width could be better. Separation of instruments is very good but could be better also. I feel the Hammonds fall short in the lower frequencies. Once again, thanks for joining in!
Dave

 

[BudP]

Dave, I felt like writing a long story so here it is.

Sound stage requires coherent low level wide band transformation from an OPT. This is one of the areas I have spent my R&D capital and time on.

In attempting to remove storage and phase mechanisms from out OPT's I have had to investigate the overall antenna transformation event in the coil. The first problem to turn up was the core, do to it's artificial slew rate, stemming from hysteresis saturation hang time.

I could have solved this using high permeability amorphous core material. A problem arose in those experiments. I could not have any capacitive coupling between coil antenna's or the resulting resonance from LCR provided an amazing peak at around 65kHz, between 12 and 40 db.

Without capacitive coupling I was loosing one half of my transformed information and that half was what provided low level wide band coherent information. So, I had to figure out a way to get commercial core, which only extends it's "power" influence to about 500 Hz, to self demagnetize and overcome that hysteresis saturation hang up. I borrowed some theory from the telecommunications industry and explored construction techniques that eventually provided what I needed. This was in 1975.

Unfortunately this relief from hysteresis spotlighted some serious problems in the coil. Over the next 20 years I experimented with methods to pick apart the "lumped" coil capacitance model for power transformers. When dielectric constants finally became widely available, for the materials used in the transformer industry, I was finally able to make a breakthrough. I could now defeat distributed capacitance and enhance the capacitive coupling across the dielectric barriers from primary antenna and secondary antenna, with engineering based materials choices. This was in the mid 1990's.

The first use of these two tools was in tube based Guitar amplifier circuits and if you Google O-Netics or my name you will get an idea of how successful this endeavor was. THD was our first customer.

For Audio reproduction transformers, I was still involved in removing the loop back storage mechanisms from loudspeaker drivers and removing response modifiers from speaker and interconnect cables. In the middle of these endeavors Vic Tiscareno and AudioPrism showed up. I had been building Nestorovic Labs power and OPT's, for the Alpha one amp, for a few years at this point. Mile' had not wanted me to change anything, just perfect and regularize the manufacturing process to eliminate the wide performance variability he was experiencing. His manufacturing manager had mentioned our name when AP was looking around for a replacement for their retiring transformer supplier

I had prototype OPT's running in a completely modified Dynaco 70, first generation cables and a pair of multi-way EnABL'd speaker systems, made up from very disparate driver elements. Vic rated the system at an 8 out of 10. Then we hooked up the silver series Debut amp he brought with. We received our first order for OPT's a week later.

Since that point in time I have been able to refine my methods and extract considerably more information transform by optimizing materials. We now provide three levels of performance, starting with OPT's that have very deep levels of detail and progressing to those with absurd levels, while avoiding false leading edge enhancements. The sound from all three levels is natural and open, with correct tonality and transient time structures. The performance remains the same regardless of power level and the more information you throw at them the more you will find transformed and available to the speakers. Even the newest digital performance levels don't cause them to congest or turn sick sounding.

My research is finished.

Bud

 

[TerryO]

I'd like to thank Bud for taking the time to give us his introductory remarks to Transformer 101. While Bud took care to present this in a straight forward, easily understood and accessible manner, it can actually get pretty complex very quickly. His "postgraduate" lectures are actually best avoided, as my own limited exposure resulted in Intense Synaptic Overload and High-Density Brain Pain.

Here's Bud in the process of designing a transformer:

I've often thought that if Bud had been born during the Inquisition, he would have been in for a really rough time.


Best Regards,
TerryO

 

[Dave C]

Today I received some new Sophia Electric 300B globe mesh plate tubes for these amps. This is the first upgrade since installing the Mundorf silver foil caps. After 1.5 hrs the sound has pulled out well ahead of the EH 300Bs I've been running. Sophia recommends at least 40 hrs of break in for the sound to fully develop. The small details really come through, more to follow.

 

[Dave C]

I had guests SET12 and No Regrets over on Sunday for an afternoon of listening. SET12 brought his monster 30lb (1645?) Hammond OPTs for us to audition on my amps. After about 90 minutes of listening we shut down and cooled and then did a quick solder job. We removed the B+ lead from my OPTs and hooked up the monsters. After warm up we listened to some of the same songs for comparison. It turns out the three of us have very similar hearing. We all felt that there was a marginal improvement in space created by the big iron. We also all felt the tonal shift was very slightly lower than before. Bass was slightly better, the highs were there but a bit softer. After an hour or so we changed back to the original OPTs and listened some more. I'll let the others chime in if they want to make any further comments on what they heard. One of the other benefits of these get togethers is listening to different music. For me No Regrets won in that category with a Chris Botti CD titled "Italia" it was some of the smoothest trumpet music I had ever heard. I ordered my own copy this morning!
For those that read back a few posts, the Sophia 300B globe mesh plates have a few hundred hours on them now and are really nice tubes, I'm totally satisfied with them.

 

[70WR]

Wow that is very nice looking - has such a clean look

Looks like a couple tubes fixin to roast a few marshmallow's.

I like

 

[djnagle]

I run the EH300Bs for a couple years, then a friend brought over a pair of KR300Bs.....WOW. That amp jumped to a completely higher level.

 

[Dave C]

Looks like a couple tubes fixin to roast a few marshmallow's.

I like

Yup I'm heating with tubes again this winter.

 

[Dave C]

I run the EH300Bs for a couple years, then a friend brought over a pair of KR300Bs.....WOW. That amp jumped to a completely higher level.

Hi there DJ, Yes that's how the Sophia tubes are. It was always good but the depth and presentation are way better with the Sophia tubes. I just hate breaking stuff in though.