Marantz MA-24...the quad was received last nite. - 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 13th October 2011, 01:08 AM   #1
diyAudio Member
 
Join Date: Mar 2005
Location: Phoenix, Arizona USA
Default Marantz MA-24...the quad was received last nite.

After unboxing, removing their tops, and blowing some stink off, I got them warming quickly and actually played music! Here they are holding the amppads to the floor.
Click the image to open in full size.

Removed a bottom cover and was please to see much room around the output-stage PS caps, so I filled a little of it on two amps with pairs of BlackGate VK-series 2200/35 bypass caps. (Original caps are ELNA for Audio 22000/50s.)
Click the image to open in full size.

Will concentrate, initially, on the inputs, replacing the RCAs with Furutechs, adding 50K TDK pots*, and, to the lower-frequency amps, adding SoniCap Platinum hi-pass filter caps for the Vandersteen 5As' bottom ends**.

Will post schematic soon.

* Will lift the original 56K load resistor too. The amps have WAY too much--as in almost 30dB--Voltage gain, so the pots will allow me to get my preamp gain control where I want it, reduce system noise slightly, and tweak the level of the high frequencies easily.
** The VS Quatros, 5s, and 7s require a preceding, inline, or built-in-the-amp high-pass filter since the speaker has none in its x-overs.

Last edited by jeffreybehr; 13th October 2011 at 01:11 AM.
  Reply With Quote
Old 13th October 2011, 08:02 PM   #2
diyAudio Member
 
Nico Ras's Avatar
 
Join Date: Nov 2005
Location: East Coast of South Africa
Nice set-up Jeffrey, what is the black box in the center?
__________________
Kindest regards
Nico
  Reply With Quote
Old 13th October 2011, 08:18 PM   #3
ilimzn is offline ilimzn  Croatia
diyAudio Member
 
Join Date: Feb 2005
Location: Zagreb
And since the originals are 50V caps, did you check that the actual voltage on these is LESS THAN the 35V rating of the black gates????
  Reply With Quote
Old 13th October 2011, 08:40 PM   #4
diyAudio Member
 
Join Date: Mar 2005
Location: Phoenix, Arizona USA
Nico, the black box in the center is a Vandersteen VCC-1 centerchannel-dialog speaker*. I've improved that, too, and haven't finished the cosmetics; that's why the black cloth is drooping.

Ilimzn, yes indeed I did. Voltage on schematic is 31; actual at my house is about 32.

BTW the amp has a completely separate (starting with PT secondaries) supply for the frontend--51Volts. I will NOT be putting 50V caps in that. :-)

Have found another spot where output-stage PS bypass caps sort of fall in and have added a couple more BGs per amp, this time 100/50 K-series.
Click the image to open in full size.

* Mine is a combination multichannel-music/home-theater system. The 8-feet-wide (NOT diagonal) screen is suspended on chains, and it's hung up, out of the way for these pics. The screen fills all but about 3" per side of the space between the V-steen 5As.

Last edited by jeffreybehr; 13th October 2011 at 08:47 PM.
  Reply With Quote
Old 13th October 2011, 10:50 PM   #5
diyAudio Member
 
Join Date: Apr 2011
Location: Pretoria
Nice setup.

I can't help thinking that keeping small children away from it would present a challenge, though. A friend of mine had his precious Linn Asaka cartridge ruined when his 2-year old son decided to investigate it.
  Reply With Quote
Old 14th October 2011, 06:43 PM   #6
diyAudio Member
 
Nico Ras's Avatar
 
Join Date: Nov 2005
Location: East Coast of South Africa
Jeff, is retired - small kids are in the distant past. Nobody will leave kit on the floor if there was any possibility of children arriving unless in a cage.
__________________
Kindest regards
Nico
  Reply With Quote
Old 14th October 2011, 06:56 PM   #7
diyAudio Member
 
jacco vermeulen's Avatar
 
Join Date: Oct 2004
Location: At the sea front, Rotterdam or Curaçao
Send a message via Yahoo to jacco vermeulen
The Phily =>
Attached Images
File Type: jpg Marantz_MA_24_largo2.jpg (322.3 KB, 360 views)
__________________
The buck stops Here
  Reply With Quote
Old 14th October 2011, 08:29 PM   #8
diyAudio Member
 
Join Date: Mar 2005
Location: Phoenix, Arizona USA
Quote:
Originally Posted by jacco vermeulen View Post
The Phily =>
That's the one even if it's not all there.

Here is a complete one.
Click the image to open in full size.


If anyone wants one that's 4222 pixels wide instead of 1280, e-mail me at jeffreybehr(at)cox(dot)net.
  Reply With Quote
Old 14th October 2011, 08:51 PM   #9
diyAudio Member
 
Join Date: Mar 2005
Location: Phoenix, Arizona USA
Finished installing the two pairs of bypass caps in all amps. Received the new IC cable, custom assembled by Sonic Craft from Neotec NEI-3001 cable and Xhadow RCAs. Had 2 jacks installed at the load ends to drive 2 amps without jumpers or splitters.

Click the image to open in full size.

Have separated the amp ends of my single/double-biwire speakercable.
Click the image to open in full size.
This too was assembled by Sonic Craft, of Tefon-insulated UPOCC copper or silver, with 2 pairs of 18g. copper for the bass/MR and one pair copper and one pair 23g. silver for the MR/treble.

The entire system sounds quite good even with lots of parts still breaking-in.
  Reply With Quote
Old 14th October 2011, 09:12 PM   #10
dadod is offline dadod  Croatia
diyAudio Member
 
dadod's Avatar
 
Join Date: Apr 2006
Location: Zagreb
Strange things on those circuit diagrams, P-channel MOSFET 2SJ115 were connectet up side down and drawn as N channel.
  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
Marantz MA-700...Popping sounds? Three Legs Solid State 7 19th August 2013 08:06 AM
Look what I just bought--FOUR Marantz MA-24s. jeffreybehr Solid State 1 2nd October 2011 07:05 PM
Crown MA-12000i / MA-5000i / MA-9000i jack2040 Solid State 4 8th March 2011 02:21 PM
marantz esotec ma-5 meanman1964 Solid State 1 28th January 2009 07:08 PM
Marantz MA 500 or MA 700 schematic krishu Solid State 0 15th March 2004 02:59 PM


New To Site? Need Help?

All times are GMT. The time now is 03:36 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