Hi,
I’m planning to capture some impulse responses from my speaker cabinets, and I know that using a neutral power amp is the best approach. While I will be doing that, I’d also like to experiment and include my VHT 2502 in the process.
Could you please advise which settings would get me closest to a flat frequency response?
Thanks!
Hi @deniki4
For closest to a flat frequency response, use a low value on the presence control. This will give more uniform negative feedback across the whole spectrum.
But your proposed setup is fun. I would not worry too much about trying to replicate a “flat” response. Think of these additional controls from the tube amp more like little tweaks you can make, similar to changing a mic or its position. The really interesting thing that you will be capturing is the interaction between the amp and the speaker – you can’t do that with a solid-state reference amp. So enjoy and experiment; I hope you discover some happy accidents 
Hi @dan
Thanks for the response!
Yes, I thought this configuration might be interesting for creating impulses for preamps. I understand I won’t achieve a flat frequency response, and that’s not the goal - I’m just curious about which settings would be the most neutral. I’ll definitely try different variations
What about the Depth control - which position for this parameter would be considered most neutral?
For depth control, it’s the same: the setting that gives you the least “boost”.
Actually thinking about this a bit more, it does depend a bit on how it’s voiced! It could have been designed in a way which sets the middle of travel to be most neutral. But the textbook answer is the one above.
When you measure the IR you will actually be able to measure which presence and depth settings are the most flat. You will need to convert the IR to a spectrum and it should show a subtle increase in the low end and top end dependent on those settings.