SET amp owners thread

[Kingrex]

I lifted both the cap and resistor at one time. Big ground loop. I have not tired just a resistor.

Ralph, I will probably at one time make a board and reset the amp on it. It saves hours of time to inspect the amp.
And I really suspect its the circuit board PS. So putting it all on a board makes it easy for a tech to work on it. Its really a messed up design. They set the guts into a folded metal box and bolted it to the bottom. You can not get a meter on anything to take measurements. The power supply is on some weird stand over the transformers and again, you cant get a at the bottom of the board to do anything. I have a nice woodshop. Its time making a box and the cost of a plate of copper or aluminum. My local guy will tell me where to set the parts if I bring them over.

 

[Alrainbow]

Rex listen to ralph of the many experts on these forums his knowledge of PSU in audio is very valuable. there are others that I feel are also very knowledgeable as well. The trouble is in order to know them you would have fixed it yourself lol.
the two above my post know I think.
now the while both are correct testing is needed to determine the exact cause.
making a new box for the psu can be helpful but I doubt it’s a cure. The gain matters so amps have less gain than say Phono pre and preamp most times.
noise gets added in gain so noise in the phono pre or pre makes more noise then just the amp alone

do you have a schematic of exactly how the amps are wired now and before any modding was done.

the owner of tripoint grounding systems also knows what’s needed. it’s why his stuff Works. He fixes everything where some makers fix what they think is needed.
Ralph is telling you this
when I had a MSB stack it had an internal grounding system that could be lifted by a setting. I’m not saying it’s always needed and I agree it should not be used but it’s also a simple test to determine causes. Note plural not just a cause , the most complex noises are usually caused by a few issues. Now as tou fix one problem others now may become more dominant hence the complexity of the task.
i don’t know the amp or if it’s worth it but to send it to someone who does know not just an industry expert (god I hate that term) is best.

 

[Kingrex]

Al, my point is simple, the local guy who looked at my amps, changed the input stage and replaced the output transformers was very clear. He needs to bill for hours upon hours of time to disassemble the amp, lay it on a bench, turn it on and test, then reassemble them. He told me to make a bettet box and that will save Thousands in labor cost to service the amp.

I personally don't know how an amp works. And I don't have time to obtain an education on the subject either. Its way to much to learn with everything else going on in my life. I am very very busy. But I don't like throwing thousand upon thousands into the trash. So at some point I will build a box like the local tech told me to do then testing and experimenting will be far less costly.

 

[Alrainbow]

Then build a box lol. But if he is changing all posted is it worth it ?

 

[Kingrex]

Then build a box lol. But if he is changing all posted is it worth it ?

Thats what burns my butt. I like a lot of what I hear. But I have not tried other big bottle amps. I would like too. But good ones are $10k and up. More low cost junk is just more junk. My whole system has matured where I need to stay at a level or I easily hear the deficiencies. I am not an unlimited funds guy. I am still curious about a ground box and a better digital source. If I can make a box and get someone to clear this ground issue for $2k????? Selling the amp as is will get me $2k. A new amp will be $10k to $12k. Thats $10k out of my pocket. Thats 2 to 3 nights out to dinner for my wife and I in Seattle.

 

[Solypsa]

.If I can make a box and get someone to clear this ground issue for $2k?????

If you do, might as well make it look cool.

 

[Kcin]

Added a Wyetech Ruby STD preamp to my Topaz recently. I will be evaluating in my system soon. Sessions I had prior with this preamp in other systems were extremely positive. My search for the original Jade is over.

I use the SET from time to time for a different taste. I really like the Topaz.

 

[morricab]

Added a Wyetech Ruby STD preamp to my Topaz recently. I will be evaluating in my system soon. Sessions I had prior with this preamp in other systems were extremely positive. My search for the original Jade is over.

I use the SET from time to time for a different taste. I really like the Topaz.

Is your version with Audio Note or Bartulucci transformers?

 

[Kcin]

Is your version with Audio Note or Bartulucci transformers?

Bartulucci-- this is one of the last one's Roger built-if not the last.

I spent a lot of time auditioning the amp in different set ups amongst his clientele and on Roger's Churchills. I also had the AN one's over here and TBH very little- if any- discernable difference to me and some acquaintances here. Roger claimed better bandwidth performance and bass quality with Bartulucci. The reality was he just could not get the AN anymore as an OEM.

While I have a love for what SETs can do most of them fall short to me. I am big proponent of simpler cross over networks and getting the right combo with the right SET works- but it is like threading a needle without eyeglasses.

The Topaz SET is one of the most un- SET like amps with SET qualities I have ever heard. It is one I can live with easily. It's a beast at about 55kg.

 

[morricab]

Bartulucci-- this is one of the last one's Roger built-if not the last.

I spent a lot of time auditioning the amp in different set ups amongst his clientele and on Roger's Churchills. I also had the AN one's over here and TBH very little- if any- discernable difference to me and some acquaintances here. Roger claimed better bandwidth performance and bass quality with Bartulucci. The reality was he just could not get the AN anymore as an OEM.

While I have a love for what SETs can do most of them fall short to me. I am big proponent of simpler cross over networks and getting the right combo with the right SET works- but it is like threading a needle without eyeglasses.

The Topaz SET is one of the most un- SET like amps with SET qualities I have ever heard. It is one I can live with easily. It's a beast at about 55kg.

I once reviewed his Pearl preamp. It was interesting but not the best in the rather elite group I reviewed it against. Always wanted to try his amps. 55kg is a good weight. A top stereo SET probably shouldn’t weigh much less if proper attention has been given to the power supply and output iron.

 

[Argonaut]

Is your version with Audio Note or Bartulucci transformers?

Bartolucci … very nice double c core output iron , when I first became interested in Aries Cerat’s 813 amplifiers I began to collect the components to build these https://www.audiodesignguide.com/Claudio845/813amp.html … however I bumped my head and having come to my senses I simply picked up the phone and called Nintronics instead

 

[morricab]

Bartolucci … very nice double c core output iron , when I first became interested in Aries Cerat’s 813 amplifiers I began to collect the components to build these https://www.audiodesignguide.com/Claudio845/813amp.html … however I bumped my head and having come to my senses I simply picked up the phone and called Nintronics instead

A bit like a Genus…

 

[Argonaut]

A bit like a Genus…

Yes … Run those 813’s nice and easy and they are beautifully linear

 

[Legolas]

Thats what burns my butt. I like a lot of what I hear. But I have not tried other big bottle amps. I would like too. But good ones are $10k and up. More low cost junk is just more junk. My whole system has matured where I need to stay at a level or I easily hear the deficiencies. I am not an unlimited funds guy. I am still curious about a ground box and a better digital source. If I can make a box and get someone to clear this ground issue for $2k????? Selling the amp as is will get me $2k. A new amp will be $10k to $12k. Thats $10k out of my pocket. Thats 2 to 3 nights out to dinner for my wife and I in Seattle.

You could look at kits, I built a few of the Audio Note NOS tube DAC kits way back. Pretty good sound for 2-3K USD.

 

[Atmasphere]

I gotta a little tweak for the community here. It isn't the sort of thing everyone can do but OTOH its not complex and no soldering.

Most output transformers are held together by 4 bolts that go thru the corners of the transformer core. They often hold the end shells of the transformer on as well. These bolts are (or should be) insulated from touching the core by either fiber (on older transformers) or nylon shoulder washers. This is supposed to prevent the bolts from being a magnetic short to the magnetic field created in the output transformer by the power tube(s).

Those bolts are usually made of regular steel, mostly out of tradition. The thinking is the shoulder washers are doing their job.

That's not exactly true. Some of the magnetic field is able to induce energy into these bolts. Its not much, but especially with single-ended gear where every drop counts, it is measurable. I did an experiment over the weekend by simply measuring the output power, changing the bolts out for non-magnetic stainless bolts and measuring again. The output power went up by about 200 milliWatts. This might not seem like much but the amplifier I tried this on was only making 3 Watts. So about a 7% increase in power! The bolts cost 41 cents each at the hardware store.

I suspect, without talking to any OPT manufacturers, that they don't use stainless non-magnetic bolts because they think the steel bolts are working fine. I first discovered this issue 35 years ago working with toroid power transformers, which are usually supplied with a steel mounting bolt that goes thru the center hole. We found that bolt tended to run hot, considerably warmer than the transformer itself. In theory it shouldn't because the magnetic field in a toroid is very compact and tends to sit inside the core. In practice though, its sloppier than that and so the bolt was a magnetic short. Replacing it with non-magnetic stainless caused the transformer to run at a lower temperature.

This is the same idea. A word of caution: doing something like this, even though you might not have to open the amplifier up, could technically void the warranty, despite the fact that over time the output transformer will run at a slightly lower temperature. If the OPT is in sealed can there's nothing for it.

 

[AudioHR]

When you want goosebumbs with your shindo,please listen to a lowther superacousta or acousta 124. they rarely appear on the used market. a perfect match the music creeps under your skin and ties you to the listening chair promised. Exsample

Nice track. It sounds good even on my IPad, lol!
I bet these speakers sound incredible.

 

[DasguteOhr]

Nice track. It sounds good even on my IPad, lol!
I bet these speakers sound incredible.

these speakers have been around since the 70s. lowther 2x pm6a (15ohm). was also offered as a kit. there are blueprints on the internet. sounds really good.

 

[christensenleif@msn.com]

I gotta a little tweak for the community here. It isn't the sort of thing everyone can do but OTOH its not complex and no soldering.

Most output transformers are held together by 4 bolts that go thru the corners of the transformer core. They often hold the end shells of the transformer on as well. These bolts are (or should be) insulated from touching the core by either fiber (on older transformers) or nylon shoulder washers. This is supposed to prevent the bolts from being a magnetic short to the magnetic field created in the output transformer by the power tube(s).

Those bolts are usually made of regular steel, mostly out of tradition. The thinking is the shoulder washers are doing their job.

That's not exactly true. Some of the magnetic field is able to induce energy into these bolts. Its not much, but especially with single-ended gear where every drop counts, it is measurable. I did an experiment over the weekend by simply measuring the output power, changing the bolts out for non-magnetic stainless bolts and measuring again. The output power went up by about 200 milliWatts. This might not seem like much but the amplifier I tried this on was only making 3 Watts. So about a 7% increase in power! The bolts cost 41 cents each at the hardware store.

I suspect, without talking to any OPT manufacturers, that they don't use stainless non-magnetic bolts because they think the steel bolts are working fine. I first discovered this issue 35 years ago working with toroid power transformers, which are usually supplied with a steel mounting bolt that goes thru the center hole. We found that bolt tended to run hot, considerably warmer than the transformer itself. In theory it shouldn't because the magnetic field in a toroid is very compact and tends to sit inside the core. In practice though, its sloppier than that and so the bolt was a magnetic short. Replacing it with non-magnetic stainless caused the transformer to run at a lower temperature.

This is the same idea. A word of caution: doing something like this, even though you might not have to open the amplifier up, could technically void the warranty, despite the fact that over time the output transformer will run at a slightly lower temperature. If the OPT is in sealed can there's nothing for it.

I always use A4 bolts for my toroid OPTs or even ITs
best
Leif

 

[DasguteOhr]

At xover coils teflon bolts no influnence because I have often seen unfortunate material choices.sorry for offtopic

 

[adamaley]

I had Silvio Pereira, CEO of Audiopax, in my home setting it up for me. And he also did the acoustic set up as he does for his clients.
One lucky thing that happened in my system was that the Tidal Contriva adjustment for the Timbre Lock was exactly the average, it means all the leds amber. So no problem when I have to set up again after changing tubes. Just put it in the amber color position.
The new Maggiore to be launched next semester will have a much easier way to set up timbre lock. It will have only 3 positions that will fit to the many types of speakers.

@joaovieira The amplifier section in your signature is empty. Are you moving on from Audiopax? If so, what have you decided on?