Go Back   Home > Forums > >

Pass Labs This forum is dedicated to Pass Labs discussion.

Which amp to build?
Which amp to build?
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
Reply
 
Thread Tools
Old 13th January 2021, 06:34 PM   #11
mrmky is offline mrmky  United States
diyAudio Member
 
Join Date: Dec 2014
Yes, I mostly agree, however I have run other speakers w similar efficiency on my ACA and they would all benefit from more power. If you have another suggestion I’m happy to research it. I know a lot of you guys have already been there and done that...
My main listening rig is Altec 605a’s run by a 40wpc tube amp.
  Reply With Quote
Old 13th January 2021, 07:17 PM   #12
6L6 is offline 6L6  United States
diyAudio Moderator
 
6L6's Avatar
 
Join Date: Oct 2010
Location: Denver, Colorado
Which amp to build?
There is no doubt that most people will run out of power when using ACA and listening at loud volumes.

Most people don’t listen at loud volumes continuously, normal listening is quieter than most people think, and so ACA is reasonable for 90% (or more) of the time.


Anyway, all the 25w class-A amps (F4 F5 F6 Aleph J M2x etc...) sound significantly and unquestionably bigger and louder than even a pair of bridged ACAs. Any of them will be the ‘more power’ you are looking for. The space and effort required for 3 or 6 dB more power past that (I.E., 50 or 100wpc) is notable and things get very large very quickly.

...which can be a lot of fun.

Read the F5T article, see what’s interesting. I’d also look for information on the Aleph J, M2x and F6.
  Reply With Quote
Old 13th January 2021, 07:26 PM   #13
Blk Dynamite is offline Blk Dynamite  United States
diyAudio Member
 
Join Date: Dec 2016
I ran an M2x on a pair of some old NHT towers (i think 86 or 88db cant remember) and it was loud. More than enough to **** off the neighbors but i vote to monoblock some F4s. Nice Swiss Army knife to have on the shelf
  Reply With Quote
Old 13th January 2021, 08:25 PM   #14
2 picoDumbs is offline 2 picoDumbs  Australia
diyAudio Member
 
2 picoDumbs's Avatar
 
Join Date: Sep 2013
Which amp to build?
Quote:
Originally Posted by mrmky View Post
Yes, I mostly agree, however I have run other speakers w similar efficiency on my ACA and they would all benefit from more power. If you have another suggestion I’m happy to research it. I know a lot of you guys have already been there and done that...
My main listening rig is Altec 605a’s run by a 40wpc tube amp.

To keep your power options you will first want to buy the 4U x 500mm chassis.
Get in on the group buy before they run out.
You can build a monster amp with it.
__________________
"If you leave this point unattached to some circuitry, an ideal constant current source will emit a small lightning bolt which will travel until it connects to something." Nelson Pass
  Reply With Quote
Old 13th January 2021, 08:30 PM   #15
2 picoDumbs is offline 2 picoDumbs  Australia
diyAudio Member
 
2 picoDumbs's Avatar
 
Join Date: Sep 2013
Which amp to build?
Ultimate 4U 500mm Chassis - Who is interested?
__________________
"If you leave this point unattached to some circuitry, an ideal constant current source will emit a small lightning bolt which will travel until it connects to something." Nelson Pass
  Reply With Quote
Old 13th January 2021, 08:33 PM   #16
Dennis Hui is offline Dennis Hui  Canada
Hoopy Frood
diyAudio Member
 
Join Date: Aug 2002
Location: Toronto, Canada
Which amp to build?
And Pico is back up.
__________________
We are fearless amplifier builders. A little heat doesn't scare us at all.
- NP 2002
  Reply With Quote
Old 13th January 2021, 08:37 PM   #17
Dennis Hui is offline Dennis Hui  Canada
Hoopy Frood
diyAudio Member
 
Join Date: Aug 2002
Location: Toronto, Canada
Which amp to build?
Quote:
Originally Posted by 2 picoDumbs View Post
To keep your power options you will first want to buy the 4U x 500mm chassis.
Get in on the group buy before they run out.
You can build a monster amp with it.
Yeah, for building a higher power amp, the OP can do far worse than
to take advantage of this unique opportunity.
__________________
We are fearless amplifier builders. A little heat doesn't scare us at all.
- NP 2002
  Reply With Quote
Old 13th January 2021, 09:31 PM   #18
2 picoDumbs is offline 2 picoDumbs  Australia
diyAudio Member
 
2 picoDumbs's Avatar
 
Join Date: Sep 2013
Which amp to build?
Quote:
Originally Posted by Dennis Hui View Post
And Pico is back up.
Time for some vegemite
__________________
"If you leave this point unattached to some circuitry, an ideal constant current source will emit a small lightning bolt which will travel until it connects to something." Nelson Pass
  Reply With Quote
Old 13th January 2021, 10:41 PM   #19
RussellKinder is offline RussellKinder  United States
diyAudio Member
 
Join Date: Mar 2015
Location: Austin, TX
Default How much Power?

Quote:
Originally Posted by 2 picoDumbs View Post
Yes but then that starts limiting the amps you can build because you've placed an unnecessary requirement on your decision process.
I bet you would have extra headroom with even 10 W. People use far less power than they think.
I don't think I really listen at excessive levels. Yet, I was surprised to see clipping lights come on quite often on my 60 wpc Japanese amp. (An Akai) back in the 1980s. Clipping finally blew the tweeters on my Infinity 8 Kappa towers. I upgraded at that time to an Adcom GFA-555 II. I seldom (but not never) saw the clipping lights come on on that amplifier.

Basically, the question is not what is your average listening level. It is what is you maximum listening level. If you want realistic sound levels, it is amazing how quickly you run out of power. A 90 dB @ 1W, 1m speaker will be about 80 dB SPL at your listening position (say 3m away from the speakers). Add 3 dB for stereo. That means you need 100W to get 103 dB SPL at your listening position.

You amplifier needs to have enough power to satisfy the loudest, peak SPL you ever expect to reproduce, not your average listening level, in order to save your tweeters. If you listen to music with a large peak-average power ratio (PAPR), then you need more power, even if your average listening level is modest.

While average db SPL levels of classical performances are usually below 90 dB, peaks can be as high as 120 dB for highly dynamic performances. (In the audience--on stage can be much louder.) ALL RECORDINGS AND BROADCASTS ARE COMPRESSED, so this dynamic range at home is impossible. You likely will only need to reach peaks of about 105 dB at your listening position. This corresponds to a 150 W/ch amplifier to reproduce. If your speaker is more sensitive than 90 dB SPL @ 1W, 1m, then adjust your power down by 50% for each 3 dB. and up by 100% for each 3 dB below 90 dB SPL sensitivity.

Please follow OSHA limits to protect your hearing. 90 dB is OK for 8 hours. 100 dB is OK for 2 hours. I personally don't like to listen to music loud for that long. Now I want a dB meter.
WHAT ARE REALISTIC VOLUME LEVELS?
__________________
Best Regards, Russell
Wherever you go, there you are. --Buckaroo Banzai
  Reply With Quote
Old 13th January 2021, 11:01 PM   #20
2 picoDumbs is offline 2 picoDumbs  Australia
diyAudio Member
 
2 picoDumbs's Avatar
 
Join Date: Sep 2013
Which amp to build?
I don't use more than 0.5 Watts on dynamic peaks with 98dB speakers

That would be 2W for 92dB speakers
So about 4W for 89dB speakers

To avoid clipping lets call it 10W, so a 25W amp should be more than enough for home use without the police knocking on your door.

Anyway nothing wrong with building a 100W amp but it's a shame not to consider the 25W Firstwatt amps as they are all excellent and more than adequate for home use.
__________________
"If you leave this point unattached to some circuitry, an ideal constant current source will emit a small lightning bolt which will travel until it connects to something." Nelson Pass

Last edited by 2 picoDumbs; 13th January 2021 at 11:04 PM.
  Reply to this post

Reply


Which amp to build?Hide this!Advertise here!
Thread Tools

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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Which T-amp and which speaker? a3aan92 Class D 43 7th November 2013 01:57 PM
which pass amp "current" amp, which voltage? ShanaVar Pass Labs 4 22nd February 2007 11:32 PM
Which is which ? fireman Multi-Way 4 2nd November 2004 06:26 PM
Which trans wire is which? billinchile Tubes / Valves 18 17th September 2004 08:28 AM
Which Gainclone ? Which PSU ? Prof Chip Amps 33 13th July 2003 05:17 AM


New To Site? Need Help?

All times are GMT. The time now is 03:46 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki