What Speakers Work best with the JLH 10W Class A Amplifier - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 Search this Thread
Old 7th August 2005, 01:47 PM   #1
diyAudio Member
 
John Biles's Avatar
 
Join Date: May 2005
Location: Victoria Australia
Question What Speakers Work best with the JLH 10W Class A Amplifier

Hello Everyone,
I built the JLH 10W Class A Amplifier a while ago and with the speakers i was using, i was told that my Amplifier sounded broken and that the sound was too sharp and hurt their ears. When I changed over to my B Class Amplifier and played my B class through the same speakers, I was told "That sounds better".
My question is what speaker suits the JLH 10W amplifier.
As it was designed at a time when large paper cone speakers were the norm, should I be heading in that direction with my speaker choice?
  Reply With Quote
Old 7th August 2005, 02:36 PM   #2
paulb is offline paulb  Canada
diyAudio Member
 
Join Date: Jun 2001
Location: Calgary
A couple of comments:
What do they sound like to you? Maybe "they" are wrong.
And, maybe there is something wrong with the amplifier. It could be oscillating, or something else. It should sound good with pretty well any speaker system.
I built a prototype Class-A a while back and it sounded wrong, it turned out I had a bad connection to the capacitor in the feedback loop. Then it sounded great.
  Reply With Quote
Old 7th August 2005, 11:32 PM   #3
diyAudio Member
 
John Biles's Avatar
 
Join Date: May 2005
Location: Victoria Australia
Hello paulb,
In relation to your question that there may have been a fault with the JLH Amp i built, I just want to say that because the JLH 10W amp and the ESP 15W class A are so easy to make up in an hour or 2, I have built 3 JLH's and 2 ESP's on Tag Strip, Vero and finally an etched board and they sound fine to me, It didn't matter which way they were built, they still sounded the same. It's possible but unlikely that I made the same mistake every time. I liked the sound, but my relatives who visited said it sound too sharp like glass, that's why i asked if this Class A works better with a certain type of speaker (eg paper cone) that would sound better to the average listener than others.
  Reply With Quote
Old 7th August 2005, 11:44 PM   #4
diyAudio Member
 
destroyer X's Avatar
 
Join Date: Feb 2004
Location: Recife - Brasil Northeast
Default If the JLH is the one with 6 to 8 volts maximum output.

Not kidding man, the best possible speaker, will be someone that will reach almost the end of the diafragm travel, when you connected the "under test" speaker to a DC supply pre adjusted to 8 volts.

It seems very obvious, but it is not.... talking serious.

regards,

Carlos
__________________
Power supply; ripple, filter, noise, stability and the use of capacitance multiplier... Portuguese and English; https://www.youtube.com/watch?v=sSm0ku1eIgg
  Reply With Quote
Old 8th August 2005, 04:04 AM   #5
diyAudio Member
 
DarkHorse's Avatar
 
Join Date: Jan 2005
Location: GuangDong
Quote:
Originally posted by paulb
built a prototype Class-A a while back and it sounded wrong, it turned out I had a bad connection to the capacitor in the feedback loop. Then it sounded great.
hi,paulb:
please post a simple schematics to express your amp's connection(feed back loop),thank you first!

regards!
WINCO
  Reply With Quote
Old 8th August 2005, 05:40 AM   #6
diyAudio Member
 
Greg Erskine's Avatar
 
Join Date: Jan 2002
Location: Sydney/Australia
Quote:
Originally posted by John Biles
It didn't matter which way they were built, they still sounded the same. It's possible but unlikely that I made the same mistake every time. I liked the sound, but my relatives who visited said it sound too sharp like glass, that's why i asked if this Class A works better with a certain type of speaker (eg paper cone) that would sound better to the average listener than others.
John,

Is the ESP amp the DoZ amp? My DoZ sounds good on any speakers I have tried it with but it doesn't play extremely loud as its only 10 or 15 watts.

Did you use the same power supply for all amps? If there is a common problem it might be there. What PSU are you using?

What output devices are you using?

What are you using for the output cap?
__________________
Greg Erskine
  Reply With Quote
Old 8th August 2005, 11:15 AM   #7
diyAudio Member
 
John Biles's Avatar
 
Join Date: May 2005
Location: Victoria Australia
Hello Greq Erskine,
I used a high ampage 28volt transformer and a 8amp bridge with about 8000uf of capacitors + 100n greencap on the power supply. The ESP amp was the Doz and I used the same transistors as listed in the Doz circuit diagram.
bc559, bd139 and 2n3055 transistors. The resistors were standard 5% and the same with all capacitors. On the output I tried from 1000uf to 6800uf electro's Caps as well as changing other cap values in the circuit. I just wanted to see how it sounded being a Class A and didn't want to spend a fortune on special Caps etc. With the Speakers I had at the time (Cheap Yamaha Bookcase 6.5inch woofer + tweeter) there wasn't a big enough differance for me to keep using the Doz over a Class B amp I had also built at the time and are still modifing as i could have more wattage without the heat. Now that I have brought some 3 way speakers, I will try the Class A again and see how it goes this time. I will built it from Scratch again and spend more time testing etc before i decide if i want to use it as my ever day amp
  Reply With Quote
Old 8th August 2005, 12:18 PM   #8
diyAudio Member
 
Greg Erskine's Avatar
 
Join Date: Jan 2002
Location: Sydney/Australia
Hi John,

Sounds like you have given it a fair go. My DoZ is quite similiar but I do have 20,000uF filter caps and the PSU is CRC as recommended by Rod Elliott. I imagine it would make a little difference having less ripple.

I came to the same conclusion as yourself. I ended up staying with a class-AB amp because it sounded just a little better, had more power and no heat.

I can't remember if I have posted a picture of my DoZ so I'm sorry if I have.
Attached Images
File Type: jpg doz rh amp.jpg (38.4 KB, 411 views)
__________________
Greg Erskine
  Reply With Quote
Old 8th August 2005, 12:32 PM   #9
diyAudio Member
 
John Biles's Avatar
 
Join Date: May 2005
Location: Victoria Australia
Hello Greq Erskine,
Nice Pic of your Doz Amp, I see you used a Elliot PCB, A lot nicer job than my amps, which were basically a copper PCB board with the layout drawn on it with a etching pen.
  Reply With Quote
Old 8th August 2005, 12:53 PM   #10
MikeB is offline MikeB  Germany
diyAudio Member
 
MikeB's Avatar
 
Join Date: Apr 2004
Location: GŁtersloh
Hmm, i've also built a DoZ, and the last thing i could say about it's
sounding is "broken" or "sharp like glass" !
I experienced a very warm/soft pleasant sound, the only reason i
rejected it was the enormous heat and the colorization.
I used MJL21194 as outputdevices, skipped the output-cap by using
a symetrical powersupply, and used a 2n5401 as input-bjt.
(I also added a small inputfilter, but should not make much difference)
The PSU was a very simple 500W,2x15v toroid, just a bridge-rectifier
and 2x22000uf. Biasing was ~1.5amperes.
I attached 3 different speakers, no problems !

Mike
  Reply With Quote

Reply


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
How does Class D work? travis Class D 16 17th April 2009 10:49 PM
350.5 modding the amp to work in more class A jfrago Pass Labs 26 24th April 2008 05:26 PM
My Class D Schematic... Will it work? thefish Class D 13 19th November 2007 12:02 PM


New To Site? Need Help?

All times are GMT. The time now is 09:49 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2