Does Pass D1 roll off treble at low volumes? - diyAudio
Go Back   Home > Forums > Amplifiers > Pass Labs
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Pass Labs This forum is dedicated to Pass Labs discussion.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 17th September 2006, 10:30 AM   #1
diyAudio Member
kiwi_abroad's Avatar
Join Date: Sep 2001
Location: Wellington, New Zealand
Default Does Pass D1 roll off treble at low volumes?

Hello all,
In the following review of the Pass D1, it mentions that at low volumes the treble is rolled off, I'd like to know if that is true?
Ultimate Audio Review of Pass D1

I simulated the I/V stage, where the volume is, and I cannot see where the high frequency roll off occurs. The opposite in fact, as volume is lowered (by lowering the resistance of R5 in my schematic, the frequency response is extended, because C1 and C2 have less of an effect. This is what I expected from looking at the schematic.

What I'd like to know is:
1. Is the review correct or incorrect
2. If correct, where in the circuit does the rolloff occur?

Cheers, Adrian
Attached Images
File Type: jpg d1_i-vstage.jpg (59.9 KB, 288 views)
  Reply With Quote
Old 17th September 2006, 10:53 AM   #2
diyAudio Member
Join Date: Jun 2003
Location: Wroclaw
I think reviewer described what he actually heard, not what measured, and this may have nothing to do with measured performance of the circuit.

According to service manual D1 has 24 step series type attenuator at the output. At low volume levels there are as many as 15 up to 23 resistors and solder connections in the signal path, and I suppose this might effect the sound to some degree.

  Reply With Quote


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Cascading volumes on a 5C3 amp bereanbill Instruments and Amps 11 19th February 2013 05:26 PM
lm3886 and differant volumes kanifee Chip Amps 22 9th July 2008 10:51 PM
Driver for low volumes TechnoMage Subwoofers 15 7th October 2006 10:41 AM
Opamp low-pass roll-off question ppereira Solid State 46 6th December 2002 03:44 PM

New To Site? Need Help?

All times are GMT. The time now is 03:21 PM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2