Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Multi-Way Conventional loudspeakers with crossovers

Dynaudio identification help required.
Dynaudio identification help required.
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 23rd September 2017, 02:40 AM   #1
Old'n'Cranky is offline Old'n'Cranky  Australia
diyAudio Member
 
Join Date: Aug 2009
Default Dynaudio identification help required.

Hi Guys.

I've been handed a pair of active floorstanding Dynaudios to refurbish.
The new owner and I have no idea what model they are.
He says there 2002 vintage, but I'm not sure if they aren't older than that.
If someone here knows what they are or has any info on them, and would like to share, that would be fantastic.

Bass driver is 24w75
Tweeter D28 / 2

Other than the Dynaudio label on the heatsink, there are no other markings at all.

List of jobs to do.

Tweeters.
Measure and sound very different from each other, so new diaphragms have been ordered.

Bass drivers.
New surrounds have been ordered. Current ones are way past use by date (gooey and lots of tears), and were very poorly installed to start with.

Electronics.
Power supply and amplifiers need rebuilding.
Fix someone's previous repair work. Fix the faults (no power up, burnt boards and resistors). Full recap.
The one I've shown here is in better shape than the other one.

Finally, a full rewire of the cabinets.
Attached Images
File Type: jpg front w grill.jpg (77.7 KB, 343 views)
File Type: jpg front.jpg (87.1 KB, 415 views)
File Type: jpg back.jpg (66.8 KB, 340 views)
File Type: jpg back bottom.jpg (137.0 KB, 343 views)
File Type: jpg electronics.jpg (271.2 KB, 337 views)
  Reply With Quote
Old 23rd September 2017, 01:01 PM   #2
system7 is offline system7  United Kingdom
diyAudio Member
 
system7's Avatar
 
Join Date: Aug 2008
Location: Portsmouth UK
I've got the old Dynaudio catalogue. Significant is that the Qts of the bass is around 0.8. The rest is self-explanatory. Usual well-controlled natural rolloff.

The D28-2 is about 89dB efficient, IIRC. Plenty of well-documented tweeter circuits around. I have no idea what the electronic circuitry is for. Protection or active drive or both?
Attached Images
File Type: jpg Dynaudio 24W-75.JPG (39.5 KB, 277 views)
__________________
Best Regards from Steve in Portsmouth, UK.
  Reply With Quote
Old 23rd September 2017, 02:54 PM   #3
boswald is offline boswald  United States
diyAudio Member
 
Join Date: Jun 2014
Dynaudio identification help required.
Ouch. Nice burned resistors on the amp. Look up that circuit board and the PS as well, otherwise it's depopulate, repair and replace time. Doesn't look too complicated. If the owner doesn't care about originality, you could go passive or dsp w/modern amps, with modern measurements.
  Reply With Quote
Old 23rd September 2017, 10:40 PM   #4
Old'n'Cranky is offline Old'n'Cranky  Australia
diyAudio Member
 
Join Date: Aug 2009
Quote:
Originally Posted by system7 View Post
I've got the old Dynaudio catalogue. Significant is that the Qts of the bass is around 0.8. The rest is self-explanatory. Usual well-controlled natural rolloff.

The D28-2 is about 89dB efficient, IIRC. Plenty of well-documented tweeter circuits around. I have no idea what the electronic circuitry is for. Protection or active drive or both?
Thanks Steve. Thought you'd have some info.
The circuit is two amps and active crossover.


Quote:
Originally Posted by boswald View Post
Ouch. Nice burned resistors on the amp. Look up that circuit board and the PS as well, otherwise it's depopulate, repair and replace time. Doesn't look too complicated. If the owner doesn't care about originality, you could go passive or dsp w/modern amps, with modern measurements.
Yes. lots of damage to both sides.
I did discuss converting them to passive crossovers, but he'd like to stay active.
So it will be strip, repair, rebuild, with a few minor mods.
Mainly uprating the burnt or heat affected parts.
The burn on the power supply is a bleed resistor. So obviously a minor re engineer of the power supply is also going to happen.

I'm going to do a post in the solid state forum to see what info they can give me for possible improvements to the amp modules.
Attached Images
File Type: jpg power supplies.jpg (244.2 KB, 125 views)
File Type: jpg amps.jpg (242.1 KB, 109 views)
File Type: jpg bass tear.jpg (184.2 KB, 124 views)
File Type: jpg outputs.jpg (355.6 KB, 111 views)
File Type: jpg bleeder.jpg (127.9 KB, 96 views)
  Reply With Quote
Old 23rd September 2017, 11:19 PM   #5
Old'n'Cranky is offline Old'n'Cranky  Australia
diyAudio Member
 
Join Date: Aug 2009
Side post on amplifier section here -> Active speaker amplifier rebuild advise required
  Reply With Quote
Old 24th September 2017, 05:32 AM   #6
eriksquires is online now eriksquires  United States
diyAudio Member
 
eriksquires's Avatar
 
Join Date: May 2013
How about a conversion? I'm not sure if miniDSP is still selling, but they had some 2 channel + DSP for sale at reasonable prices.

Best,

E
__________________
All of my successes and failures can be explained by my attempts at getting a girlfriend. All of them.
  Reply With Quote
Old 24th September 2017, 05:43 AM   #7
Old'n'Cranky is offline Old'n'Cranky  Australia
diyAudio Member
 
Join Date: Aug 2009
One of the things that drew my customer to these was being able to plug his pre into them and no setting up needed.

I did see a 2 channel dsp amp, but i think the cost and set up would exceed what hes after.

So far the combined parts list is substantially below what a single dsp setup costs.
  Reply With Quote
Old 26th September 2017, 10:00 PM   #8
Old'n'Cranky is offline Old'n'Cranky  Australia
diyAudio Member
 
Join Date: Aug 2009
For those playing at home.........

In my thread in the solid state section regarding the amplifiers.
Well, the amps are history.
The boards won't allow repair or rework, they just fall apart at the touch of a soldering iron.
Currently in discussion with the owner as to what he wants to do in that regards.
I.E. passive conversion or an ice/mini dsp plate amp swap.


I sent Dynaudio an email asking if they had any info about these.
They got back to me today.

They passed the photos around and no one knows these speakers.

Their best guess is they were one of their very first active speakers built around late 70's early 80's.
They can still supply drivers, which is pretty awesome in it's self, but that's the end of what they can do.

Otherwise the owner and I are still in discussion as to the next step.....
  Reply With Quote
Old 27th September 2017, 07:49 AM   #9
Lojzek is offline Lojzek  Croatia
diyAudio Member
 
Lojzek's Avatar
 
Join Date: Feb 2012
Location: Croatia
The easiest approach would be to design a passive filter, something like Dynaudio DM 2/10. The size of the enclosure is already in the ballpark. I have got the same drivers, only 3 way with added 2" midrange dome.
__________________
A good dialogue makes you feel like a changed person, not like you have won or lost the competition.
  Reply With Quote
Old 27th September 2017, 12:22 PM   #10
Old'n'Cranky is offline Old'n'Cranky  Australia
diyAudio Member
 
Join Date: Aug 2009
Passive would also be the cheapest option.
Then again, He'd then have to buy an amplifier, so that would destroy any cost savings.
Depending on amp he chose, could even be more expensive..
I've given him the options and ball park costs.
I await his decision
  Reply With Quote

Reply


Dynaudio identification help required.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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Surface mount diode identification required Old'n'Cranky Solid State 6 16th January 2015 09:25 AM
need a little help with identification Junk Audio Tubes / Valves 2 17th June 2014 08:26 PM
Part identification required arky Parts 10 22nd April 2014 09:57 PM
FS: Dynaudio Dynaudio Dynaudio eded Swap Meet 5 23rd April 2013 06:27 PM
Need identification if possible. es44 Full Range 2 11th September 2008 08:38 AM


New To Site? Need Help?

All times are GMT. The time now is 04:36 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki