What makes the Bloom around instruments . . .

I own a Pass XA30.5. To my ears, it sounds pretty neutral. I'm not doubting you about the difference in bloom you heard between the Pass and the Spectron. But I am wondering whether the difference in bloom is attributable to something that the Pass amp ADDS or to something that the Spectron amp SUBTRACTS. Here are two possible scenarios:

1. The Pass amp ADDED bloom to the system, whereas the Spectron amp did not.

2. The Spectron amp SUBTRACTED bloom from the the system, whereas the Pass amp did not.

I don't know anything about the Spectron amp, other than its excellent reputation. But as an XA30.5 owner, I can say that it does not seem particularly additive, at least not in the way I associate with descriptors like "bloom," which makes me think of euphonic harmonic distortion. This observation about the XA30.5 is confirmed by Stereophile's measurements, which show that its harmonic distortion is mostly 3rd order, and that it is otherwise rather harmonically neutral.

In light of that, I am inclined to believe that scenario (2) is the more likely of the two, and that the Pass amp's advantage over the Spectron was that it was allowing the bloom from the recording, or from other components, to be heard, while the Spectron was masking it. Of course, this is speculative.

It would be interesting to hear more about the system used to audition the two amps.

Bryon

Thanks for all of the responses. It makes sense.

Since it appears that it's a product of either my AC, Spectron or both, that's where I'll start to look.

It can't be the Wadia S7i since the bloom was there with the Pass but not with the Spectron.

Chuck

Bryon, I also think Chuck's speaker cables and such are more resolving than your anti cables. So maybe more details/resolution are heard in Chuck's system. Your two systems and rooms are different. Just a hunch, what do you think?

I run a 6SN7 preamp in front of a pair of digital monoblock amps and asked the same question.

Secondly, has anyone really heard bloom in a live amplified/un-amplified performance ?

Define bloom. Different components can introduce attractive sonics to a system that some may call bloom. Some CJ components to me have bloom. I have also heard very good designed preamps introduce a more attractive sonic signature that some may call bloom but not the CJ sonic signature. For example, direct heated tube preamps, transformer coupled preamps, CDPs, DACs have a sonic signature that is very attractive but I would not call that bloom IMO. I have owned the Pass X-250 (not the .5 series) and that amp had a sonic signature that was sligtly softer with a kind of golden sound. To me the amp was trying to sound what some would say is a tube sound. They may be right. That is probably what you are hearing with the Pass amp. The specton will offer a clearer sound without that golden sound. That is probabaly what you are hearing. Rx8man is hearing some a very good preamp in front of his digital amps so he has a more attractive sound versus what I would call "bloom".

So I think the attractive sound comes from a components design.

Hope this was helpful.