"modern" switch on the 2:90

[dass101]

Hello,
I am using a Triaxis with a custom made 100W tube power amp.
I studied the schematic of the 2:90 and decided to "upgrade" my power amp to get it closer to the 2:90. One big part of the 2:90 sound is the feedback network, with the presence, deep and modern switches, so that's where I started.
I decided to skip the "modern" switch, not being sure about what it does, and installed a "depth" knob (similar to SLO's mod).
I now run the amp with the presence at about 10 o'clock and the depth at 1-2 o'clock.
My question is: what is the "modern" switch?
Can anybody describe what it does to the sound? Is it worth installing? (I play medium-high gain with the L2 yellow, with low DV - 2)
Also, am I missing much not having simulclass?
Thanks a lot!

 

[jaquetapus]

Modern makes the power section have more of a ballsy aggressive Recto kind of voice. I like it, I run most of my patches with both deep and modern. As far as Simulclass, I think that's part of what gives Boogies that vocal midrangey quality. I'd suggest you borrow or test drive one and try it out. I love mine.

-dave

 

[desertdweller]

The 2:90 is a great amp, but it really comes to life when you switch on Deep and Modern. You've got to hear it yourself, it blows away most all the competition IMO. The Deep mode gives it a huge powerful low end, and like the previous poster said, the modern voicing gives it some punch and redefines the upper mids.

 

[cscotto]

The modern switch on the 2:90 does the same thing as the modern switch on the 2:100. They both cut out the negative feedback, which makes the amp more "unruly." Negative feedback is feeding part of the output signal back into the input. I think it acts almost like a comb filter in that it smoothes out the signal and controls the type of distortion at this last stage in the amp. Taking out the negative feedback unattenuates the signal. Here is a link:

http://en.wikipedia.org/wiki/Negative_feedback

 

[ostia man]

I only hear a 2 maybe 3 dB boost in modern mode when the presence is way down. if the presence knob is at half or full i cant hear any diffenence'
is it supose to be more noticeable?
in my dual recto the difference is nigth and day.

sorry for the mini hijack

 

[PG13]

The 2:90's "Modern" and "Deep" settings combined with a Triaxis set to "Yellow" powering a closed back 4x12 cabinet is a tough act to beat IMHO. I'd put that against any competing amp.

 

[chipaudette]

I'd like to clarify a previous person's post a little...the modern switch doesn't cut out the negative feedback, it just changes the frequency content of the negative feedback.

There are some folks out there who are all about "NO NEGATIVE FEEDBACK FOR ME!" thinking that that'll always sound better. I just wanted to clarify that, in my reading of the 2:90 schematic, there is always some form of negative feedback.

The presence knob, the deep switch, and the modern switch all change the properties of the negative feedback in order to impact the sound of the amp, but the negative feedback is always there.

Enjoy!

Chip

 

[JohnDNJ]

The 2:90's "Modern" and "Deep" settings combined with a Triaxis set to "Yellow" powering a closed back 4x12 cabinet is a tough act to beat IMHO. I'd put that against any competing amp.

Thats how I ran my tri\2:90 for 10 years. You really dont need anything else as
far as that pre\power amp goes...it's a beast.

 

[MesaGod666]

Thats how I ran my tri\2:90 for 10 years. You really dont need anything else as
far as that pre\power amp goes...it's a beast.

Seriously. The 2:90 is quite possibly the best Power Amp on the market. I have never needed anything else.

 

[dass101]

Thx guys,
By looking at the schematic I also concluded that the "modern" switch does two things: lower the negative feedback (giving the amp a more open sound) and also shifts the frequency of the presence knob, to allow more upper mids to be affected by the knob.
I think I'll give it a try as soon as I'll get a push pull pot.