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Have opportunity to buy BHK 300's or Pass Labs 250.8 for my Thiel 3.7's- thoughts??

I think I will take the plunge on one of two as they are within my budget.
pgastone
pgastone OP
79 posts
 
it would be a very far stretch- used single units range around $4k (give or take $200)- and there’s the matter of finding 2 of similar age and tube usage.
I was originally looking to spend some $5k for solid state- i realize tubes would be more but 8 really do not want to go much beyong $6k.

Quicksilvers  V4’s have a very good reputation - i know of several audiogoners that swear by them- and are hand wired for much less (mono’s) but of course the transformers are key.


pgastone OP
79 posts
 
And FYI
I just spoke to Mike Sanders- it was a pleasure and he in fact discouraged using the V4 with the Thiel 3.7's (which he seemed quite familiar with).   The source impedance of the amp is too high and would not match with the speaker's fairly impedance dips.  

This is something that unsound had been mentioning.

On the other hand he explained that the mono 120's are specifically designed for more difficult loads and should handle the Thiels well.  

One of the problems of course is that this kind of information rarely readily available unless the amplifiers have been reviewed and appropriately tested.

I want to look more into this- very interesting.   I just wonder what kind of output impedance would then be considered a good match- yes obviously the lower the better but that is just a relative comparison.  I would like to know about the matching in more absolute terms.
unsound
7,329 posts
 

Keep in mind that the Thiel 3.7's don't just dip into sub 4 Ohm loads, they live there over most of their operating conditions. That's why I caution those to be wary of amps that merely claim to be "Stable for musical transients". Thiel's recommended power was 100-600 Watts per channel, but that was for a standard 8 ohm load with the understanding that the amp would double down as needed into the actual load. Into a nice, safe  rounded 2 Ohms that would be closer to 400-2400 Watts. Keep in mind that as the impedance drops so does the sensitivity. So that 400 Watts minimum might seem like an awful lot, but, for adjusted sensitivity; it's about the same as 100 Watts into 8 Ohms. Some of the amps you previously mentioned are indeed robust, sturdy amps with most speakers and then some, just perhaps not ideal into your particular Thiel 3.7's.

I couldn't find more recent independent measurements of Pass Labs current offerings. While I suspect the more recent ones might be better in this regard, I also suspect that these older ones are not irrelevant. As much as I like some of their gear, their independent measurements have been somewhat disappointing of late.

I tried to include this before but for some reason it wouldn't take.:

https://www.stereophile.com/content/pass-labs-int-150-integrated-amplifier-measurements


doctorrob77's avatar
doctorrob77
24 posts
 

I've been a Professional musician most of my life and you must ask yourself, am I a music person, or a gear person? Every audiophile should know by now that sound signature is subjective and personal. The only true way to know what's best, is to know what sounds good to you, and that's all that matters IMHO.

kingharold
304 posts
 

I use a Pass Labs X150 and two First Watt F3s to power my DIY horn speakers.  In my estimation Nelson Pass is a genuine genius.  You won't go wrong with Pass.

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