The "Elsinore Project" Thread

Jump to Latest
#5,642
"NBAC" Update:

It looks like there can be an "NBAC" version of the Elsinore Mk6. But the devil is in the details.

It will not be with the CDC tweeter, it has just proved to be too problematic, on three fronts. One is the low sensitivity, the second is the low impedance, but it was the third that was the real killer. It was hoped that a minor change to the existing waveguide was possible and for a short while it looked like OK. But there was a sharp null at 9KHz, If it had not been there, it would have meant the small change to the waveguide, it would have worked with both tweeters. Further modification, and now there was a dip around 4KHz that was fatal. At that point it was realised that it wasn't going to work.

On the other hand, the SS D2608 works great. No wonder, it was designed for that tweeter and getting it to work with another very different tweeter, with hindsight, it was always going to be a stretch. But not from the lack of trying.

So what is on offer is an "NBAC" version with the D2608 tweeter, and the combination (i have already done the crossover modelling in SoundEasy) looks really excellent. The two sets of drivers will work together very nicely.

Any comments?
 
#5,644
I will let other do that. I can't chase down every rabbit hole. I am already familiar with that waveguide. But even that won't sort out problem one and two listed.

In DIY we do have some flexibilities, so even here there are limits. Form one, a large amount of money already investing in stock of the existing D2608 waveguides. May I also point out that 3D printing is not as exact as these are, and they need to be.

So flights of fancy is one thing, but I am in the business of making realities work.

I can have a pair of NBAC/D2608 working in a matter of weeks (even a week if I made the effort), I am already down that route and a mountain of work behind me and in the straight run home.
 
#5,645
All I am saying, I can't stop in mid stream, too far down the road to have it working and many hours involved. But I am indeed curious as to what the aluminium drivers are going to sound like. There is treatment around 7Kz that is not too heavy-handed, so this is better behaved that I thought a hard cone drive would behave like. It is almost certain to sound different.
 
#5,647
I am 90% down the road I am on, the cabinets are designed, ready, painted, an forgotten number of measurements etc... I can scrap all that effort. But I think I should finish it. Sometimes you have to make decisions and see it through, even if there are dozens of other ways to do it. Also, those with earlier Elsinores (this has been the policy since the beginning) will be able to change/upgrade/or just try it out.

Here are the boxes, decision made, they are going to be used:

20230317_190346.jpg


Anybody with older Elsinores will be able to try it out. If you have Mk1 or Mk2, the square hole can easily be converted (I have done this a number of times) and they can try aluminium cones, something I never thought likely.

I am looking forward to hearing it and making the last stage of tweaks done.

Those who want to use the CDC tweeter, there are other possibilities out there. To low sensitivity and low impedance, it's not a match. If they made a different version, then I certainly would not be disinterested, but just too many things not to be compatible with what the Elsinore's aims and targets are.
 
  • Like
Reactions: Mikerodrig27
#5,649
Low impedance? I have certain requirements as to the final system impedance plot. I thought it was obvious that I saying that the combination of low sensitivity and low impedance, and that I don't want the system impedance to drop down to 3-4 Ohm. I thought that would have been obvious. I am sure the CDC is fine for a 4 Ohm speaker, but Elsinores are not 4 Ohm speakers. Never will be.
 
#5,651
Jonasz said:
Why use a high distorting valve amplifier when using a low distorting loudspeaker thus "destroying" the excellent performance of the Elsinores? Serious question. 🙂
Click to expand...
Great question.
First, no amp will sound good when clipping. We are talking, or what I am trying to explain is far below clipping, and for my taste, below 2% with a tube amp...
My understanding (very amateur) .. Tube amplifiers built and design well distort mostly on even harmonics.
While its is distortion, the secondary harmonics actually blend well with the primary frequency's and can be loosely compared to one singer singing the same note in harmony with themselves (like over dubbing).

Opposite, of tube amps is sand based amps as far as distortion profile...
From what I understand, the distortion profile is on the odd harmonics and akin to folks singing out of key.
It became very clear, early on that silicon based amplifiers sounded horrible at similar distortion levels and the trade offs available that were worth effort to switch had to be done with as much of a reduction in distortion as possible.
Hence, the ever popular lowest distortion wars....

Back in the day, folks did talk about and were concerned about tube distortion but below a low percentage number generally was not considered horrible.
While I speak of these things as if I was there, believe me most happened well before my time.
I only can base whats above on what I have learned in the last bunch of years. I took the jump into tubes, and dont know if I can ever look back.
What I love about the tube amp is the warmth it provides, and my belief is because of the harmonic nature of a well setup tube amp...

All that said, at least for me there are a ton of downsides. Thats another discussion!
 
#5,655
#5,657
AudioFanMan said:
I only can base what's above on what I have learned in the last bunch of years. I took the jump into tubes, and dont know if I can ever look back.
What I love about the tube amp is the warmth it provides, and my belief is because of the harmonic nature of a well setup tube amp...
Click to expand...

I fully understand your comments and well said, and it reflects what others have said.

But I have a strange belief that you like what the tube amp does is lower distortion of some yet (by most) unidentified kind. The 'warmth' should be there in the first place. And if it is not, then it is distortion that does not allow you to hear it.

I know that I could go on, but my ideas why is often viewed as dangerous.

If you like the sound better, then I am betting that it is because you are listening to lower distortion. You can pretty much bet on it too.

And it isn't even a tube vs solid-state question. But I too love my tubes.

The harmonic explanation I am less convinced about. While Earl Geddes and I disagree on some things (via PMs), I am in agreement with him that 2nd order is pretty much inaudible. It is almost totally masked. What about the 3rd? That's an interesting case, because it can actually add a bit of spice to the recording. This was pointed out to me by Phil Punch of Electric Avenue Studios (which has a rather interesting connection with Chesky Records) and he viewed 3rd order as almost a legitimate thing to add as part creatively. Also, those great tape recordings of classic recordings, they have lots of 3rd harmonic distortion, and they are loved by so many and they sound great.

I don't think the warmth that you are hearing is caused by those harmonics that is supposed to cause warmth. I don't see evidence for it. Rather, the warmth you now hear is the result of distortion no longer getting in the way. The warmth is for real!

Now let us see what comments that generate? 🤔
 
  • Like
Reactions: AudioFanMan
#5,658
zman01 said:
Is there a typo there - I think you meant "ERSE Audio"?
Click to expand...

zman01:

You're absolutely correct. I wasn't paying attention and was autocorrected.

The USCoils website allows you to place items in a basket and calculate shipping costs. Whether they have stock and are shipping product is an open question (at least for me at this time), but their website appears to be functioning as you might expect. Who knows -- maybe Erse's successor is legit!

Regards,
Scott
 
#5,659
Heat dissipation in the coil is a concern and it has to be taken into account. I set up my lab power supply and set the limiter to 1 Amp. I measured around 3V across the coil and left it for 30 minutes. It warmed up, but the P-Core mass absorbs a lot of the heat generated by the wire. But I was particularly interested if the coil was noticeable warmer than the P-Core material. I could not detect any difference at all. That means that the P-Core material is doing a good job sinking heat.

I then upped it to 2 Amp and heat amount to 6 Watt continuous, and it up quite warmed quite a bit, Again the P-Core does a good job, but now you could only touch it for about five seconds, but no damage done to finger. Basically the thing is acting as a large wire-wound resistor under these tests. And if you have an external resistor, then it needs to be around or more than the internal resistance. In the Elsinores we end up with around 4R series external.

But I would say that this Jantzen inductor is as small as I would comfortably make it. It is about as compact as I would make it. If you use a larger inductor with lower resistance than 3R2 and if it is quality, then you cannot go wrong, you just have to deal with the physical size.
 
#5,660
Joe Rasmussen said:
I fully understand your comments and well said, and it reflects what others have said.

But I have a strange belief that you like what the tube amp does is lower distortion of some yet (by most) unidentified kind. The 'warmth' should be there in the first place. And if it is not, then it is distortion that does not allow you to hear it.

I know that I could go on, but my ideas why is often viewed as dangerous.

If you like the sound better, then I am betting that it is because you are listening to lower distortion. You can pretty much bet on it too.

And it isn't even a tube vs solid-state question. But I too love my tubes.

The harmonic explanation I am less convinced about. While Earl Geddes and I disagree on some things (via PMs), I am in agreement with him that 2nd order is pretty much inaudible. It is almost totally masked. What about the 3rd? That's an interesting case, because it can actually add a bit of spice to the recording. This was pointed out to me by Phil Punch of Electric Avenue Studios (which has a rather interesting connection with Chesky Records) and he viewed 3rd order as almost a legitimate thing to add as part creatively. Also, those great tape recordings of classic recordings, they have lots of 3rd harmonic distortion, and they are loved by so many and they sound great.

I don't think the warmth that you are hearing is caused by those harmonics that is supposed to cause warmth. I don't see evidence for it. Rather, the warmth you now hear is the result of distortion no longer getting in the way. The warmth is for real!

Now let us see what comments that generate? 🤔
Click to expand...
Hello All,

Tubes have been some of my best fun for a long time. Noise is always a struggle. If you do measurements you can average away much of the noise and see distortion products peaking out of the weeds.

You can filter and regulate away most of the power supply noise. That is a lot of work and expense. Then tubes can make a lot of noise on their own.

If you carefully select and adjust a Shunt Regulated Push Pull 12AU7 line stage you can minimize the 2nd Harmonic. With careful selection of the tube and adjustment of the operating voltage and bias you can find the sweet spot where the 3rd Harmonic nulls.

With one hand on the voltage control and the other hand on the bias adjustment you can dial in on the FFT sweet spot.

One project was a SET 12B4A headphone amplifier with a custom output transformer. The power supply required much more time and money than the output transformer. See the attached FFT and THD+N sweep plots.

Yes, the H2 distortion is likely masked as the H3 distortion is likely masked. Tell @gedlee that the higher harmonics are part of the package. See the classic SET stair step harmonics in the FFT plot.

You can see the 1/f noise increase with decreasing frequency.

Thanks DT

12B4 68X + Shunt FFT 220m.png
12B4 with regulators Sweep .png


Another 12B4A FFT with different PS regulation. Lower noise floor, 60Hz peak is lower than before. Filtering and regulating the PS is a pain.

12B4 with regulators FFT.png

SP500 5 12 21.png


I have spent way too much money on things like a Keysight N5752A 600VDC bench power supply, Keysight Source Measurement Units and Audio Analyzers.

Even plot JFET Curves
PF5102 IDSS.png
 
Last edited:
  • Like
Reactions: zman01 and Mikerodrig27
You must log in or register to reply here.
Top Bottom