Any other SS amps with output transformers out there except Hellborg?

[Mr. Foxen]

I'd think that those "edge cases" would be less rare amongst musicians who over years and decades have honed the ability to hear minute subtleties of tone and pitch.

Think a lot of the musicians into output transformers and stuff are guitarists who have honed the ability to hear nothing above 3khz.

 

[agedhorse]

Wow, hope the marketing guys don't jack you on your coffee break

They live in fear of the potential of a catastrophic power failure, so like everything in this world we have come to terms with the self limiting nature of mutual destruction

 

[beans-on-toast]

With the right metrics and a good understanding of how they relate to sonic performance, I think it's possible to get a very good picture of how something behaves in the real world.

I have some fancy test gear but my best piece of equipment is my ears. I'm not advocating seat of the pants design. When you're chasing tone, I find that tweaks based on listening make all the difference. Especially when it comes to transformer tweaking. I find that can be a long and difficult process with a lot of back and forth listening.

People are playing with auto mixing (as opposed to automation) but most songs still go through the creative process of mixing by ear. I like to think that amps and studio equipment still need that final step in the process.

 

[Mark Reccord]

I have some fancy test gear but my best piece of equipment is my ears. I'm not advocating seat of the pants design. When you're chasing tone, I find that tweaks based on listening make all the difference. Especially when it comes to transformer tweaking. I find that can be a long and difficult process with a lot of back and forth listening.

People are trying automate but most songs still go through the creative process of mixing by ear. I like to think that amps and studio equipment still need that final step in the process.

I certainly didn't assume you were advocating seat of the pants design.

 

[seamonkey]

I'd think that those "edge cases" would be less rare amongst musicians who over years and decades have honed the ability to hear minute subtleties of tone and pitch.

Maybe, but maybe the musicians are hearing artifacts that really have nothing to do with the tone and pitch?

In one DBT study I read, one musician test subject was tested on a tube amp and SS amp. He could tell the different. It turns out he was detecting ripple intermodulation distortion on the tube amp. The experimenters didn't account for this. When they fixed the tube amp he could no longer tell a difference.

On another DBT vinyl versus CD, some of the test subjects always preferred the vinyl. The experimenters then recorded vinyl to CD, and those same test subjects no longer preferred one over the other. They had a CD with wow and flutter, crackles and pops and now liked it. The ones that preferred CD originally, did not prefer the vinyl recorded CD.

When the odd artifacts are accounted for it seems differences can fade for the test subjects.

 

[seamonkey]

It's not a gimmick, it's a design choice. There are many very early transistor audio amp designs with output transformers. Early 70s Univox solid state heads had a transformer and an impedance switch.

Also you can read this about McIntosh solid state amps.



If the transformer loads the output transistors at the optimum impedance, then you get full power out of the amp. As the article linked above points out, in theory you can just reduce load impedance and get more power. The issue is current and heat dissipation. Few amps show ideal power increases as impedance drops for this very reason. You should get 2x the power at 4 ohms compared to 8 ohms, but relatively few amplifiers can in fact do this. Wouldn't it be great to take an amp rated at 100 watts at 8 ohms, drive a 0.8 ohm load instead and get 1000 watts?

Early transistor designs were - well, were early. They didn't have all the much power, and so impedance switch was handy to squeeze out every single watt. Transformer just aren't needed now.

Even today. Several manufacturers include a impedance switch from 4ohm to 2ohm that does not change the wattage. They're rated the same to either load. They can do this by changing the rail voltage, or limiting the output.

From some comments it sounds like Hellborg should have added more interstage transformers also. The more the merrier. And designed a high voltage SS amp output where the transformer actually transformed something to something.
And included several cap coupled stages for those who prefer that.

 

[beans-on-toast]

I certainly didn't assume you were advocating seat of the pants design.

Not that there's anything wrong with with a little of that.

When I have a nagging problem and am wondering how to resolve it, sometimes a little intuition helps. Experiment by throwing in a capacitor and see. Based on the results, then figure it out.

 

[BadExample]

They live in fear of the potential of a catastrophic power failure, so like everything in this world we have come to terms with the self limiting nature of mutual destruction

So that microwave beam you have pointed at marketing might take down the California grid? If so, I'm sure you have designed it so it will run long enough to electronically neuter them before the collapse.

 

[agedhorse]

So that microwave beam you have pointed at marketing might take down the California grid? If so, I'm sure you have designed it so it will run long enough to electronically neuter them before the collapse.

I was thinking about marketing some high profit tin foil hats in a way that makes it irresistible to them...

 

[Passinwind]

I was thinking about marketing some high profit tin foil hats in a way that makes it irresistible to them...

I think this franchise is available: Aluminum Foil Deflector Beanie

..........................................Link Removed ......................................

 

[BadExample]

Just add a Nike swoosh.

 

[Bassmec]

I'm not saying it's bad, I'm saying it can be done with EQ

Yes of course it's perfectly possible with an EQ but might I suggest something like a Urei 546 EQ as they had the same iron core audio transformers as the sonically world famous 1176ln compressor.
Other than that there is always the Neve 1073 EQ section with those marvellous sounding marinair transformers.
What you have yet to work out is that a better quality of sound has very little to do with superior electrical performance.
Ergo Lower distortion is not a big seller in over drive and fuzz pedals.X

 

[Martin Beer]

One notable example of an SS amp (albeit for guitar) with an output transformer which hasn't been mentioned yet is the Pignose 7-100. It's an odd design; I'd read that it was based on a circuit used in early transistor radios.
I never particularly cared for mine, but they do have their fans.

 

[agedhorse]

One notable example of an SS amp (albeit for guitar) with an output transformer which hasn't been mentioned yet is the Pignose 7-100. It's an odd design; I'd read that it was based on a circuit used in early transistor radios.
I never particularly cared for mine, but they do have their fans.

Very standard early transistor topology, based in par on the approach of tube amp topologies. Saw this a lot with Germanium PNP power transistors.

 

[beans-on-toast]

Saw this a lot with Germanium PNP power transistors.

They used Germanium power transistors in the JMI VOX T60. It gave them trouble with oscillation issues that caused the devices to blow. They switched to Silicon power transistors in later amps, used huge heatsinks, and had a temperature sensor based thermal shutdown circuit in their later amps. They had much more success.

 

[B-string]

The old: "Learn something new every day". I was not aware JMI dabbled in SS, I thought the SS were all Thomas Organ "Vox" (US destruction).

 

[agedhorse]

Germanium had a lot of undesirable characteristics for a semiconductor... including a steep tempco.

 

[beans-on-toast]

The old: "Learn something new every day". I was not aware JMI dabbled in SS, I thought the SS were all Thomas Organ "Vox" (US destruction).

JMI had their own amps. They sold controlling interest to a British company that set up Vox Sound Equipment and they sold only the US rights to Thomas Organ. Thomas Organ designers helped them resolve issues with their transistor designs. At some point Jennings left and started a new company. He teamed up with Dick Denny again and redid the AC30. I had one for a couple of years but sold it because I didn't think that it sound as good as the early 60's ones. In the mid 80's I bought a Marshall built reissue AC30 which I still have.

 

[Coolhandjjl]

What's the best output transformer for metal?

 

[beans-on-toast]

Germanium had a lot of undesirable characteristics for a semiconductor... including a steep tempco.

The small signal germaniums did well in pedals but there was a lot of variation from one unit to the next. I bought some NOS Mullard ones a while back for some fuzz pedals. Granted they were prescreened and matched but the prices were nuts.