Gregfisk
Quick Q: Did this brightness issue start only after adding the Butler amp, or has it always been lean clean, and bright sounding? If so, you have your answer on the amp not being the culprit.
Ever wonder how many amps are out there which do not double their outputs when the load impedance is halved? A bunch.
Ever wonder too, why the owners of these amps arent lineing up posting about top end brightness?
Did this system you have ever sound otherwise than it does now? Exactly when did this brightness clear and clean non musical adventure first rear up its head noticeably? Id look there then.
Id bet good money to or with whomever, the items I noted above if addressed, would remedy that fatiguing sound you are encountering, without undertaking wholesale component change outs. Of course youll find out when another amp is employed. maybe.
AS Tvad says repeatedly do ensure the ??? amp doubles its power when the imp of the loudspeakers is halved though. Considering any other sort which does not is just time well wasted
or so it seems. Such advice will surely narrow the field of amps to look into for your needs. Given the Butler's output, start with those in the 400 wpc @ 4 Ohms... and up, as you already have that on tap.
Never mind the voice of the amp
or associated gear, setup and cabling, its simply always the power aspect.
Its funny the notes of system fixes follow the trends of their posters. Gear houhnds point to the gear as the bug a boos, room treatment aficionados allude respectively to adding items there, cable mavens exclaim buy better wires, etc. well, to each their own aim. And after all, its only money.
BTW, there's nothing wrong with those approaches or philosophies, I just feel all of the rig needs careful scrutiny, not merely the stuff you rest on the rack or a shhelf.
it might be as simple as one said the spikes or footers of the 7Bs... or their need for a platform of sorts.
Putting another engine into a car that has bad brakes, a slipping transmission, and or poor suspension, only remedies motor problems.
The thing which confounds me here is Ive never heard anyone remark the 7Bs were aggressive in their upper ends. Never. This is a first for me
so in fact Im going on their popularity and no mentions of their so apparent shortcomings. I know that Butler isnt contributing adversely to the situation too.
FYI
* Hand selected/matched 6SL7GT Twin Triode tubes
(One per channel)
Fully regulated Tube Heaters with Delayed Soft Start
(10-15 second turn-on delay)
Load Adaptive Vacuum Tube Driven output circuitry
Modular power channels with a seperate massive, oversized heatsink for each channel
Independent AC Secondaries and Rectifiers
with 60,000µF per channel filtering
SPECS
Rated Power (all channels driven):
2 x 250 Watts RMS per channel @ 8 ohms
2 x 400 Watts RMS per channel @ 4 ohms
1 x 800 Watts RMS Bridged (Mono) @ 8 ohms
Freq response: 20Hz to 20kHz (+/- 0.5dB)
Power Bandwidth: -3dB, 50kHz
THD: <0.10% @ 8 Ohms, <0.15% @ 4 Ohms
S/N Ratio: Better than 120dB (A-Wtd)
Slew Rate: 15v/µsec
Input Sensitivity: 2V for 250 Watts into 8 Ohms
Input Impedance: 47k Ohms
400 wpc into 4 ohms!
If thats not enough power for the 7Bs, maybe other speakers or as said, another amp is needed, depending on which one of those two is the newer or more desired. Personally the 7Bs could be more easily improved upon IMO.
Anything is possible I guess. The Aerials may just hate the Butler or vice versa.
Despite Tvad's well meaning but abreviated listing of proposed areas to find possible avenues for a resolution, I made mention of my own listings as the result of my own exp... and found out about it the hardest way imaginable, by spending money that did not need spending, had I looked into the system as just that a system. The sum of it's parts all working together to perform properly and provide enjoyment for the owner.
The underlying caveat here and elsewhere has always been, "Everything matters, and everthing makes a difference."
Perhaps it has changed now.
I do pray your issue is resolved quickly and without more frustration or length.