boom3

This is the horizontal model, the Ask The Historian forum can give you more detail

so, when was the change over to the front ports?

Thanks Chris, as usual you have shed light on a complex subject

I like the ASR reviews because Amir is doing things no one else, certainly not Stereophile, is doing right now. He is using a consistent, defendable, set of metrics (no Klipschorns on stools in somebody's driveway) he is not using a lot of fluffy adjectives to puff up his advertisers' products; and he can admit when he's made an error. His call-outs of several examples of high priced trash audio products I am sure have made the manufacturers squirm. I do share one concern about Heritage that both Stereophile and Amir point out-cabinet resonances. In all the uproar about Sterophile's bungled review of the Klipschorns, I did not see any discussion of the midrange cabinet resonances discovered. One would think that Klipsch could engineer these resonances to be lower in frequency and amplitude that the reviews have uncovered. Having said that I don't always agree with him or any other reviewer. His speaker reviews concentrate on bookshelf systems and has not tested many floor standers. His idea of perfect response is output declining with increasing frequency (like pink noise). I don't know why he thinks that is "perfect"; you'd have to ask him.

Thanks for finding the Beveridge patent. The original Beveridges were incredible speakers, and created a curtain of sound you could walk though, turn around and perceive the performance as if you were now in back of the performers. They are one of my two faves of all time (the Klipschorn of course being the other; have not heard Jubilees yet)

Acoustic Lenses Bell-Laboratories-Record-1949-10.pdfLike so many things in audio, these were devised at Bell Labs

They are acoustic lenses, developed in the 1940s to improve the dispersion of horns. As horn design became more sophisticated, the extra expense and appearance of acoustic lenses was no longer appealing, and they were dropped. I think only JBL really promoted them, but they may have licensed the technology to others.

Is the Dope still published?

When "NRA" meant something completely different...

I'd like to know what cart that is and who is making his styli

https://www.youtube.com/watch?v=BAAgGcGAIZU&feature=emb_logo

That's us. In happier times, get a load of this from 1964:

thank you Backfire. As a former tech, this is exactly hat I was looking for. I may PM you later with questions thanks again

Thanks for the replies, however, let me re-phrase the inquiry: If one has two tube amps identical in every way, except for one output transformer having a lower secondary resistance than the other, which will be abetter match for Klipschorns?

So, in matching tube amp to Klipschorns, what is the most important factor in getting a satisfactory result? Is it damping factor? Power output? Amplifier class (SET vs P-P)? I realize each has its advocates, but I am just curious as a life-long SS user.

"Fusion power is the power of the future, and always will be"

How I feel after hours of sitting in the same chair whilst teleworking from home...

On the Gulf Coast we like French dressing on pizza.

The Equivalent Series Resistance (ESR) and Dissipation Factor (DF) varies between caps, so the capacitance value per se is usually not the significant factor . I recapped my B3s with WIMA caps and noticed no audible diff. I recapped really for long-term stability. Most electrolytic caps start out about 10-20% above their labeled value and then drift downwards, with ESR and DF increasing over time. Film caps of any type usually keep their values for life, although if exposed to heat from vacuum tubes or in a car, they can be damaged. I tested some 40+ year old caps recently, they were right on their 2% tolerance. I don't have an ESR or DF meter but I doubt these particular caps (CRC metallized polypropylene hermetically sealed) are much different from the day they left the factory. Mylar caps have higher DF & ESR than their poly brethren and therefore I avoid them.

B&O used a variant of the moving iron called micro moving cross, that had a cruciform piece of ferrous material that the stylus moved over the four poles of the coils and fixed magnet. It was most famously used in their SP-12 line. I had a SP-12A in my vinyl days and I loved it. It was slightly rolled off at the top, but with bright speakers it sounded very neutral. The test reports of the time noted its exceptionally low distortion.

As Paul said long ago, "Yawns or goosebumps?"

I've seen Tuba Skinny for years and I keep thinking I will see myself in one of their many Royal street videos

Can't really beat Tuba Skinny

AC contractors generally charge about 5X list (Mouser, Allied, etc) for motor run caps (not including labor). Just sayin'...