Comments on Ray Samuel's Stealth?

[Kieran Comito]

I never listen louder than 9 oclock. Starting point is 6 oclock right? Mark, I know you have told me that it does not bother your ears at all to listen that loud, but my ears would be ringing if I listened at 10 oclock.

[john_jcb]

Except for this testing I thought 9 was too high for the R-10's and the HR-2. I cannot fathom listening for very long at 10.

[Sean H]

Voltage output of your guys' source could be a bit different too. Cables could be a small factor in some way. Sorry, just thought I'd throw that out. Then again Mark probably does listen quite loud like a madman!

[markl]

He he. (Well, now that I look at it, it's actually between 9:00 and 10:00, but still... ) When my dad came over and had a listen to my rig, I forgot to turn it down to normal levels. When I fired it up, he must have jumped 6 feet in the air, he dropped the CD case he was holding! I know that's loud, but it doesn't bother my ears at all, no ringing, nothing. I have had my hearing checked in the last 4 years, and they're just fine, completely normal. I would never do anything that would cause fatigue or irritation-- I value my hearing way to much to risk losing it, and losing my drug of choice-- music!

In my younger days (not so much now, sadly), I was an avid concert-goer. I've seen hundreds of shows, so I'm used to loud rock, and that's what I like. If I were to turn it down much more, I would get bored and disengaged. For me, it's only at higher volumes that headphones open up and allow you to climb inside the sound. Still this is nowhere near concert-level sound. A while back I used my Rat Shack SPL meter and on the loudest material averaged 85-90db at my listening level.

EDIT-- Sean H makes a good point. I was actually able to lower the volume level of the HR-2 when I switched over to my Sony 555ES "Hot Rod" which has a new output board with its own power supply, and is supposed to result in increased gain over stock.

Mark

[markl]

Update....

I just fired up the SPL meter again, and I realize that since I got my Hot Rod with its increased output, I've been listening to loud rock at 90-95db average!!!!! That's just too damn loud for safety, I'm glad I decided to do the test again. With my previous source, this volume setting resulted in sound averaging between 85-90db, loud but more sensible levels.

I've moved the knob on the HR-2 down to the 9:00 level to start, I'll see how that goes, and see how much more I can take off the volume to keep my enjoyment and my ears at the same time. Thanks everyone for pushing me to dig out the SPL meter and do the test again. I was not aware I had it up so loud.

Mark

[davidmiya]

Hi guys,

I was wondering if the Stealth would be capable of driving the AKG K1000's properly?

[Ray Samuels]

The Stealth was not designed to drive the K1000.
Even though at the Chicago meet, one of the headfier did listen to the Stealth with the K1000. Not recomended, May be in the near future, if there is enough of need for a K1000 amp.
Ray Samuels

[Nightfall]

Originally posted by Ray Samuels
The Stealth was not designed to drive the K1000.
Even though at the Chicago meet, one of the headfier did listen to the Stealth with the K1000. Not recomended, May be in the near future, if there is enough of need for a K1000 amp.
Ray Samuels

Of course, one can do the optimum thing, as I and some others, I am sure, plan to. I'll be purchasing a great tubed power amp, or tubed monoblock power amps to complement Ray's superb Stealth preamp section, which should address ANY need the K1000's, or speakers, in addition, might have!


JC

[davidmiya]

Originally posted by Nightfall
Of course, one can do the optimum thing, as I and some others, I am sure, plan to. I'll be purchasing a great tubed power amp, or tubed monoblock power amps to complement Ray's superb Stealth preamp section, which should address ANY need the K1000's, or speakers, in addition, might have!


JC

No hurt in asking

[Tuberoller]

Early on,I was a bit disappointed with the Stealth after I got it home. I was trying to find the wonderful sound I had heard at the meets but it was missing. Ray made some changes to the amp after the meets and I could certainly hear them. I have no real idea why he would mess with the flavor, but he did, and it was a very bad thing. I returned the amp to him a few times for him to return it to the earlier circuit configuration and after a few trials he got it right. I was reluctant to post and agree with John's impressions but I just was'nt feeling good about the Stealth and was gonna post my impressions,negative or otherwise, yesterday. Ray's latest circuit change has returned the Stealth to the sound I remember at both the meets and that of the prototypes I listened to in the early stages. Give me a few days to listen to this latest circuit configuration more closely and I'll post my full review by Monday or so. Sometimes audio designers do things that completely befuddle me and this was certainly one of those times. I have to admonish any designer to learn something from this,especially Ray. The next time you get the kind of positive feedback the Stealth got at the Detroit and Chicago meets,don't screw with the flavor.

In all fairness,I don't know if any other manufacturer would have been afforded the same luxury of having the opportunity to correct mistakes as Ray did but understand I was working from reference sonics I had heard before. It also helps that Ray lives nearby. It does not help that Ray is very stubborn and is an extremely busy man but all seems to have worked out in the end.

[darkclouds]

Thanks for the update tube.

I guess the question then is which circuit will be on the production units?

[markl]

tuberoller,
Can you describe the differences you heard between the two samples? Audio is so subjective (not to mention system-dependent), I wonder if others would have preferred the changed version? Can you or Ray comment on why these changes were made? Maybe there were sound design reasons why the newer circuit was implemented that are lost by going back to the original? Is the unit that john_jcb commented on the revised version, or the original version? Are the production versions going to be based on the original circuit? This is confusing.

Mark

[arnaud]

Tuberoller,

Thanks a lot a this info.

Ray, can you confirm the production units will be what Tuberoller is reviewing this week end?

cheers,

Arnaud.

[arnaud]

Originally posted by markl
tuberoller,
Can you describe the differences you heard between the two samples? Audio is so subjective (not to mention system-dependent), I wonder if others would have preferred the changed version? Can you or Ray comment on why these changes were made? Maybe there were sound design reasons why the newer circuit was implemented that are lost by going back to the original? Is the unit that john_jcb commented on the revised version, or the original version? Are the production versions going to be based on the original circuit? This is confusing.

Mark

Oups, you were two minutes ahead of me and are asking the right questions

Arnaud

[Ray Samuels]

When designing any electronic components & building it in stages,
you tend to spend so much time in development & research to make that component works to it's optimal by tweaking those little resister, caps & diods. You would order the parts that would be enough to built one or two components but in many values as your tweaking the design. Once the audio components sounds the way your happy with, then you decide this is the part list that I would be needing to built the rest of my units with.
That was the case in my ordering the parts for 30 Stealths. I made a mistake in the reading of value for two identical in value diods that are in series with the 12 VDC power supply that supply the voltage to the fillement ( heater ) of the tubes. As both output tubes are wired in series to share the 12 volts thus each having 6 volts going through it's filement. The mistake was that some how I read the 300ma diods as 3000ma, so I ordered enough for all the Stealths. Two Stealths were built with the wrong diods, as the tubes were pulling 1250ma for the heater the diods were getting hot & 3 volts were dropping across them, this made the tubes fillement hungry for voltage causing the balance of the sound shifting to the wrong direction. So the tubes were getting only 9 VDC instead 12 VDC.
The problem was found & corrected with 3000ma diods which are much higher rating than what is needed in the design.
No Stealths have been shipped yet. The two productions Stealths have the correct diods of 3A in them NOW.
WE are HUMAN & human makes mistakes.
Ray Samuels