I just found this cheap tweak for BHK power amps(and probably the preamp too…). Get some mouse pads and place it on top of the amp as shown in the photo. I bought(AUD$10 for 2) some from amazon and they were rubber backed and quite substantial(weighed around 100g each), don’t use light mouse pads.
I started with two pads and have now gone up to four pads. The improvements are more clarity, less harshness when listening at higher volumes and better bass definition. I think the pads are damping out vibrations that affect the tubes.
Please share your finding if you do try this tweak.
The only thing of possible concern is that plasticizers in the mats could outgas over time (especially under the influence of constant heat) and permanently mar the paint finish on the amp. I’ve found the paint on the BHK250 cover to be somewhat susceptible to absorbing oils and contaminants.
I am aware of the degradation possibility with the pads and heat so I’ve ensured the pads have the rubberised base facing up with the cloth touching the BHK top.
I’ve also been checking the BHK cover every few days and after almost 3 weeks using the pads there has been no impact to the BHK top, fingers crossed…
Thanks for the comments.
p.s. The picture I attached shows the 2nd pad sitting on top of the bottom pad as it looks better than the rubberised base facing up…
Not what I would recommend for the pre. It’s not advisable to block the slotted cover which is slotted for a reason, to ensure proper cooling for the tubes. Interesting idea for the amp, though.
