SETs and Horns

[Atmasphere]

Forget measurements for now , have you tried new tubes same tubes and let burn in for min 50 hours.
Then with your ears tell us how much better the new tubes sound hahahah. reg reliable I can’t see how a tube is more reliable then a SS device
what parameters did you use to make your claim

A lot depends on use. A tube will degrade slowly over time since the filament circuit uses the same tech as a light bulb and is subject to the same issues; quite independently of how the other elements in the tube age- which they do! IME, power triodes hold up much better than power tetrodes or pentodes on this latter account.

However, corrosion is a problem for semiconductors in a way that I've not seen in tubes. Older semiconductors in anything made in the 1960s to the 1980s should be regarded with some suspicion- noisier than they should be, less gain and far more likely to fail if pressed into service. Certain transistors, if you see them in older gear, should be replaced on sight (2SC458 is a good example) on this account. By contrast, a tube stored over that same time will not see any significant performance degradation.

 

[K3RMIT]

See this is why I love your posts I always learn
thanks for the reply. i have heard some say this
can be. SS in questions be measured like a diode for leakage ? Or reverse conductance ?

 

[Atmasphere]

See this is why I love your posts I always learn
thanks for the reply. i have heard some say this
can be. SS in questions be measured like a diode for leakage ? Or reverse conductance ?

Yes, but that won't tell the whole story.

 

[K3RMIT]

Ok I get you
revised

 

[Atmasphere]

Ok I get you
but just to make a point on tube replacement
for me I go about 1/2 of maker recommendations
i know it maybe too soon but it’s easy to hear new once past the 1/2 mark. so am I correct ?

I replace tubes when they are bad. You can replace a used tube that is perfectly good with a new one that isn't.

 

[K3RMIT]

deleted by me

 

[Atmasphere]

So you don’t listen hahaha
all i was saying is simple
long before it goes bad the sound is if you compare
same for old caps
but it’s ok to do as anyone wishes

It sounds as if you missed my point! If a tube is bad its not going to sound right. The circuit is built with the understanding that to sound right, the tube that its using will be a good one. Tubes can be bad right out of the box- low transconductance, leakage, microphonics and noise. Those all have audible effects. Listening IMO is implied.

 

[K3RMIT]

I replace tubes when they are bad. You can replace a used tube that is perfectly good with a new one that isn't.

Please remove my comments I have way to much respect for you and all you have done and continue to do for auDeo. my comments were not meant to be offensive but I feel they maybe.
As always thanks for the time you take here

 

[K3RMIT]

There are many industry expert titles here few deserve the name you are one who stands above most ones here.

 

[Rensselaer]

There probably is a little crosstalk, but in terms of electro-magnetic issues its no worries at all. The layout of the circuit would have greater effect!

So it is called crosstalk, now I know. Is that one reason for some to find triodes better?

 

[Atmasphere]

No. Triodes have greater linearity. The more linear, the lower the distortion so should sound better on that account. Typically their output impedance is lower too.

 

[Rensselaer]

I had horns that did shout. They were BD-Design tatrix horns designed to boost down to 150 Htz from single hi-efficiency mid-range speaker. Mine were powered by a pair of Lowther PM-3 speakers. Bert Doppenburg (designer of BD-Design horns in the Netherlands) advised me that Lowthers have "Hi-Ferric" metal filings glued onto the voice coils that eventually get loose and obstruct the coils passage, so I ordered my PM-3 speakers special, silver voice coils and no "Hi-Ferric" coating. Bert advised me that I may have eliminated the Hi Ferric problem but the cone shape/manufacturing of Lowthers caused a mid-frequency augmentation and that would cause a shout, and he was correct. They did sound fantastic playing horns, but also tended to shout. He advised I change my Lowthers for AER speakers (Germany) and I would eliminate the shout, but they cost a bundle. I now use Thrax Lyra reflex speakers, and they sound great, but I do miss the "presence" of horns.

I have since this post replaced the Thrax Lyra speakers with vintage Altec A7-500's VOT horns, and they sound great. No shout.

 

[Atmasphere]

I have since this post replaced the Thrax Lyra speakers with vintage Altec A7-500's VOT horns, and they sound great. No shout.

In the old days we used to put damping materials on the outside of the horn structure, which helped the horn (which is cast aluminum) to be more relaxed.

 

[morricab]

In the old days we used to put damping materials on the outside of the horn structure, which helped the horn (which is cast aluminum) to be more relaxed.

I will probably do similar with my 18 sound XT1464 horns. They are not metal but could probably benefit from some treatment. What do you recommend for damping? I was going to try to get some auto door panel damping material but is there something better?

 

[Atmasphere]

I will probably do similar with my 18 sound XT1464 horns. They are not metal but could probably benefit from some treatment. What do you recommend for damping? I was going to try to get some auto door panel damping material but is there something better?

These days I would be using the EAR 2003 material but its a bit tricky to get. 3M makes a damping epoxy that would work nicely in certain places on the horn. It cures to a soft state.

 

[DasguteOhr]

Bostik Blu-Tack 801103 Klebemasse, ungiftig, 12 Stück : Amazon.de: Bürobedarf & Schreibwaren

Bostik Blu-Tack 801103 Klebemasse, ungiftig, 12 Stück günstig auf Amazon.de - Große Auswahl von Top-Marken

www.amazon.de

really good damping, you can also solve it again if you want to sell the speaker again. Exsample

 

[MarcelNL]

sculptors wax is also nice to dampen, it needs to be heated slightly and kneaded a bit before applying but is sticky enough and works well. I've used on the Tesla Tweeter horns when I used them, currently I have some plasticine on the JBLs as the wax is in storage due to moving house.

 

[Rensselaer]

I am new to this YouTube stuff, and using the poorer sounding iPhone to record this as well, but I just recorded a song from a Pablo recording (not audiophile) of Johnny Hodges playing "I got it bad and that ain't good" (I love the way he bends notes on a saxophone) to show that my newly acquired rough vintage A7's do not shout (though a little loud perhaps to cover the sound of the wood cutter with a chain saw in the field next to us). Any advice from all of you who know a great deal more about this stuff than I, please weigh in.

 

[bonzo75]

Thanks. Can you please play some more recordings, which show vocals, piano, drums, violin, orchestra, etc, that will give a better idea

 

[PeterA]

I like the music, but I agree with Bonzo to post additional music selections. I like the camera angle of the video because it shows the listening perspective but when I make iPhone videos, I try to hold the iPhone right where my head is in the listening seat. That will give a truer representation of what you are hearing when listening to your system I think. Thank you for making the effort to post the videos. It’s always nice to hear different systems especially SET horn systems in an SET horn system thread.