NAD Ampeg PF500 and some questions about 5 pos. Mid switch

[Spirit of Ox]

Hi,
I just got one of these Ampegs last week and even gigged with it last Sunday. I'm really impressed with the amp and it's tone. I normally play Hartke amps (lh500, ha3500). The Hartkes are very transparent in tone compared to Ampeg. The Ampeg just has the complex mid range to it that I'm not fully used to.
So there's this 5 position switch which gives you different mid voices and I'm only really noticing a difference when you crank the mid knob all the way. If I drop it down below 8 than I really don't hear much of a difference. For example. I have it on position 5 which gives me a nice high mid boost. It's a great sound with the mid knob all the way up and the bass and treble set at 1:00. If I turn the mid knob down I lose the mids and some treble and it sounds much darker.
Is this normal for this amp and other Ampegs? Perhaps Jimmy Miller or any other Ampeg aficionado can chime in.

 

[basscapes]

While I'm not answering your Q exactly (I KNOW JimmyM will chime in shortly!), I WISH the SCR-DI had that 5 way mid selector ala, PF/SVT...

 

[blubass]

I have a PF500 and the mid frequency selector is actually pretty sensitive and works great for myself, though I don't make big EQ changes from flat very often. It may be possible your cab isn't as sensitive so you need to crank the volume to get a perceived change in tone.

Are you just playing with the amp and trying to figure it out, or are you trying to achieve a certain tone that you can't seem to find?

The range of the mid selector isn't as noticeable from 1 to 2, or 2 to 3, as it is jumping from 1 to 4 let's say.

The midrange knob is +10db or -20db. As such, you'd need to boost the mid knob, or alternatively cut the bass and treble knobs to get a higher perceived volume boost in the midrange, as it's designed to cut more than boost.

If you use the Ultra low switch, it will boost 40Hz by 2db, while cutting mids at 500Hz by 10db, which is significant.

The associate mid selector is 1= 220Hz, 2= 450, 3= 800 4= 1.6kHz, and 5= 3kHz.

Do you know in general what happens to bass tones when you cut or boost each of those frequencies? That would also be important in understanding the amp.

Best of luck, I hope the info helps!

 

[Spirit of Ox]

I have a PF500 and the mid frequency selector is actually pretty sensitive and works great for myself, though I don't make big EQ changes from flat very often. It may be possible your cab isn't as sensitive so you need to crank the volume to get a perceived change in tone.

Are you just playing with the amp and trying to figure it out, or are you trying to achieve a certain tone that you can't seem to find?

The range of the mid selector isn't as noticeable from 1 to 2, or 2 to 3, as it is jumping from 1 to 4 let's say.

The midrange knob is +10db or -20db. As such, you'd need to boost the mid knob, or alternatively cut the bass and treble knobs to get a higher perceived volume boost in the midrange, as it's designed to cut more than boost.

If you use the Ultra low switch, it will boost 40Hz by 2db, while cutting mids at 500Hz by 10db, which is significant.

The associate mid selector is 1= 220Hz, 2= 450, 3= 800 4= 1.6kHz, and 5= 3kHz.

Do you know in general what happens to bass tones when you cut or boost each of those frequencies? That would also be important in understanding the amp.

Best of luck, I hope the info helps!

Thanks for you help. Cutting and boosting those frequencies doesn't affect the bass tones to much except maybe the the first two positions. I favor 4 and 5, especially 5 when boosted. I didn't realize that the mid knob was more for cut. Is this a passive Fender style tone stack? My hartke LH500 has that type of tone stack where mid is cut only.

 

[floridagatorfan]

 

[Spirit of Ox]

Thanks for the video, and I watched all of the videos pertaining to the Ampeg PF500 but I didn't see this one. This really makes sense since the mids need to be boosted to hear them come through.
Cool this really helps me understand the switch now.

 

[The Chuck]

It took me a while to get there with this too. When I found a setting I liked, I would start fiddling with it a few days later... and so on and so on.... I'm happy with where I am now. Position 3 boosted to 2:00. 2012 Fender Jazz PF800.

 

[floridagatorfan]

Thanks for the video, and I watched all of the videos pertaining to the Ampeg PF500 but I didn't see this one. This really makes sense since the mids need to be boosted to hear them come through.
Cool this really helps me understand the switch now.

Glad this helped you. I had to watch this video to understand how it worked myself

 

[ahc]

Is this a passive Fender style tone stack? My hartke LH500 has that type of tone stack where mid is cut only.

No. Ampegs use a Baxandall/James tone stack which enable you to boost or cut bass, mids, and treble. Flat on an Ampeg is all knobs at noon (mid switch at #3). Flat on a Fender tone stack is 2, 10, 2 (B, M, T knob number... not "o'clock").

 

[Spirit of Ox]

Ok, that's what I thought but It seems with the positions 4 and 5 that I really like, you have to boost the mids up all the way to really hear it. It makes sense now after playing it all night. I tried a few settings and I like bass and treble at 1:00, mids all the way up, and mid position 5. I like the high mid boost on my P bass, really cuts through.