Top end strain with Smash and Seductor combo

[Thijs]

Hi there, everyone!

The question I am asking is in regards to the kits that my dad recently completed.
His system consists of 2 mono wired Seductor amps and a Smash preamp with the supplied upgrade installed.

Besides the expected (and reducible) hum and microphonic properties of the Smash he's running into another problem that we can't quite figure out. When listening to songs with a strong top end, female vocals for instance (specifically but not limited to Adele - Million Years Ago) there is an audible top end strain happening. It almost sounds like it's an issue with the recording but that's not the case. I'll provide some details about the setup below. Strangely when using his Advance Acoustic transistor pre amp the strain is gone. There are clear sonic benefits of the Smash in comparison to his previous pre-amp but this issue makes it difficult for him to fully commit to the Smash. Have any of you ever experienced something similar?

Details about setup:
CD player: Advance Acoustic MCD 203
Pre: Smash with supplied upgrade
Power: 2x Seductor wired for 4 ohms
Speakers: Totem Arro 4ohm nominal 87dB/1w/1m
Interlinks: We don't know for sure as we bought them many years ago. Nothing special I believe.
He has installed gain attenuators of -15dB at the input of the Seductor which did help with a gain issue he was having.

All components are connected to mains via basic mains cable (240V)
All mains cables are connected to a basic grounded power bar strip which is in turn connected to a grounded outlet.

All equipment resides on an IKEA shelf. I've included a image of the system, shown without the smash but the preamp would reside in between the two power amps. (Sorry for the poor quality, it's a still taken from a video.)

Fun (but maybe important) fact: He lives in a new apartment which is directly connected to an old watertower. The system itself actually resides inside the tower on a separate floor.

If I've left any important details out please let me know and I will do my best to supply any and all information I can collect.

Thanks so much in advance for any suggestions!

Kindest regards,
Thijs

[Doc B.]

He lives in a water tower? Cool! Your dad's name isn't Professor X is it? Though I don't have first hand experience I'll go out on a limb and say that using the Smash in a water tower listening room shouldn't be an issue, as long as you went to the trouble to take all of the water out.

Can you clarify a bit what the high frequency strain is like? Is it distortion that is only on the loudest notes (that would of course include Adele punching out the final phrase or two of her songs). Is it sort of a compressed sound, where the treble is emphasized more then the other preamp? Or is it maybe sibilant distortion that only happens on words starting with S? If it is a distortion issue make sure the voltages are all correct in the Smash for starters.

If it is not distortion but just a more bright sound, the Smash may well have a little bit higher output impedance than the transistor preamp. Sometimes interconnect cables can have more influence in a system with a higher output impedance device in the signal path. A cable that might sound "detailed and open" connected to a low impedance preamp might sound overly bright connected to a high impedance one. Or it might just boil down to letting the gear break in a while longer. A lot of edgy and compressed sounds go away after a hundred hours or so.

[Paul Birkeland]

Or it might just boil down to letting the gear break in a while longer. A lot of edgy and compressed sounds go away after a hundred hours or so.

That's what came to mind for me!

[Thijs]

Thank you Dan and Paul for providing suggestions.

I think you might be right with the last suggestion. It is by no means a sibilant noise issue. It's seems to be overly bright and slightly distorted as you say. He did do some more cross checking with his previous system and now he's hearing the same thing on his old system without any bottlehead equipment and even a different CD player.... Right. So I guess he's got some figuring out to do. Might just be the CD for some reason or another. Meanwhile the BH equipment has been put back to good use and breaking in nicely.


Regards
Thijs