Mark Audio CHR-70 Application Thread

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
dMar-Ken70 progress picture:

attachment.php


Nothing very exciting yet, but now that I've got a few of the tricks down, the second box will go together pretty easily.
 

Attachments

  • 07032010.jpg
    07032010.jpg
    334.6 KB · Views: 1,115
That's what's slowing me down - those are all the good clamps I have, so it's preventing me building the second box.

Notes for those who have built Onken's before: you'll note that the outer walls seem longer than strictly necessary - they are, but only because the bloke I had cut the timber got lazy and cut 12 backs instead of 4 backs and 8 sides. Doesn't matter, they'll get lopped off.

Further note: using a nailgun (and glue) to build up the side wall assemblies saves a lot of time and clamps ;)
 
frugal-phile™
Joined 2001
Paid Member
Further note: using a nailgun (and glue) to build up the side wall assemblies saves a lot of time and clamps ;)

A brad gun is very useful... even if you are finishing the ply the sidewalls can use brad nails from the inside. If we are going to veneer the box, ie most of the time, the brad nails get used thru-out the assembly

dave
 
keith_correa, you're welcome

please consider my previous post as a guide only, of course. I'm not trying to persuade any to not build these great little speakers (well, not tiny, but pretty small). The Mark Audio drivers in modified form are quite critical of edgy sounding electronics and sources, and wiring, and...

I imagine the stock ones are more so, as EnABLing smooths out a lot of "edginess". I am not trying to play "audio snob" to any, as those who know me know that I am not, nor am I driven by the cost of a particular component to consider it to be "good"

The comparison to the MS Avant 906i loudspeakers is accurate though. I suspect any design using the CHR-70 drivers (whether stock or EnABLed, or is it eNabled?) will be critical of all that is in front of them in the audio chain.
 
Hey Dave, I've got a new project for you - the uMarOB-70 :D

Construction takes only seconds - indeed, everything you need is in the box.

Bass response could be said to be a bit thin, in much the same way that water is a bit damp, but even like this these drivers are very involving. I was only going to set them up downstairs to break them in, but they appear to have ended up on my desk ;)
 

Attachments

  • uMar-KenOB70.jpg
    uMar-KenOB70.jpg
    484.6 KB · Views: 1,047
Hey Dave, I've got a new project for you - the uMarOB-70 :D

Construction takes only seconds - indeed, everything you need is in the box.

Bass response could be said to be a bit thin, in much the same way that water is a bit damp, but even like this these drivers are very involving. I was only going to set them up downstairs to break them in, but they appear to have ended up on my desk ;)

Haha, that's brilliant! just the driver "in" the box, wired straight to the amp?
 
Yeah, when they're shipped they're supported in the box by a bit of folded cardboard - add a bit of tape to keep the cardboard box-shaped and screw them in with the supplied self tapping screws and you have something that sounds damn good for the invested time, if not for the money ;)
 
The cross-section can be changed as long as area remains the same. One has to be careful if made too narrow. This brings the sidewalls close to the driver and can cause a "cupped" or "chesty" midrange colouration. Port can be moved from the bottom, to the front, back, or side. Just keep it as close to the bottom as practical. You can mount it on a wall, or lift it up as required.

dave

Still something about halfTower. I've done some thinking and came up with inner W160 and D108. H784,2 as in halfTower. I'd like to do front facing rectangular vent but I have no idea how to calculate it. In halfTower round vent is done with D2" and L5".

Any ideas? W would be (maybe) that 160mm. Should I do it "under the H784,2 or "in" it (kind of minus to height..)

Is this even possible :p
 
listening comments, w/Nuforce Icon digital amp...

Had a chance to listen to the speakers again today. Listened mainly to Seal's "Soul" cd ( a great cd if you like soul with a slightly modern take).

equipment chain:
cdp--->Microline Drive--->Icon--->speakers

my basic comments:
WAy more bass (as expected due to the T-amp---ok, "D-amp", not based on the Tripath chip), due to decreased dampening factor of the amp. Depth is flattened, width remains about the same. Did I mention WAY more BASS!

So far the Icon DAC/headphone amp/amp is very enjoyable. If I could only get the great soundstage of the Nakamichi, and the tonality of the Icon, I could be set for a long, long while.

Next up, the McCormack DNA without resistors, then with. Then a Sanken based 20 watt SS , then some tubes...
 
Last edited:
frugal-phile™
Joined 2001
Paid Member
Still something about halfTower. I've done some thinking and came up with inner W160 and D108. H784,2 as in halfTower. I'd like to do front facing rectangular vent but I have no idea how to calculate it. In halfTower round vent is done with D2" and L5".

Any ideas? W would be (maybe) that 160mm. Should I do it "under the H784,2 or "in" it (kind of minus to height..)

You can convert the round port to a rectangular one bt keeping the same cross-section area and the same length. As the aspect ratio of the rectangle increases you will be adding "damping" to the port.

dave
 
Had a chance to listen to the speakers again today. Listened mainly to Seal's "Soul" cd ( a great cd if you like soul with a slightly modern take).

equipment chain:
cdp--->Microline Drive--->Icon--->speakers

my basic comments:
WAy more bass (as expected due to the T-amp---ok, "D-amp", not based on the Tripath chip), due to decreased dampening factor of the amp. Depth is flattened, width remains about the same. Did I mention WAY more BASS!

So far the Icon DAC/headphone amp/amp is very enjoyable. If I could only get the great soundstage of the Nakamichi, and the tonality of the Icon, I could be set for a long, long while.

Next up, the McCormack DNA without resistors, then with. Then a Sanken based 20 watt SS , then some tubes ...


dude, what took ya so long?

try something like 6P15P-EB (SV83) in P/P with the Hazen suppressor grid mods - (this will not work on EL84/6BQ5 types with G3 internally strapped to cathode)

my lil' Scotti (ElCheapo variant) is quite delightful configured as such - an aggressive rebuild to a decrepit SCA35 should easily achieve similar results.

If as some speculation might have it, this could cause some intended consequences or reduce component life, it's too soon to tell, since I only listened to it for a couple of months before becoming consumed with a home reno project. But if it's good enough for someone like Eddie Vaughn in incorporate in a custom amp that he had to ship from Arkansas to Vancouver Island, I'll assume he's not worried about smokin' er up.
 
what took so long?

They were "finished" middle of last week, I finally got em from Mike on Friday, had a listen to an A-88, and wasn't really that impressed. But as soon as I got em home into familiar surroundings, I was blown away. At this stage of the build, they are pretty fugly.

Mike's gonna wrap them in Birch veneer, then I'll decide on a proper finish.

Chris, thanks for the excellent instrux on veneering.

my listening comments are being posted as I hear them. These speakers deserve to have the best possible amplifier in front of them. Whether that be class D or tubes or Nelson Pass design, or, or,

The little Icon really is something with these, but as I stated, flattened the image somewhat. Although perfect for a desktop, not perfect in a main system (the Icon). Mike is planning on using them as (large) desktop speakers. We will also remove the OBs from the Spirits, and replace them with the dMar-Kens. This could very well be a very interesting experiment. Personally, I could live happily with either the Jordans or the CHR-70s. But the high value of the CHR-70eNs make it a no brainer. hmmm 2 pairs of CHR-eNs for less than the cost of one pair of Jordans?

I was thinking that a sca-35 re-make or similar would be a great "Nanook Audio" product and could be a complete solution for many. or a Moose preamp/Mos-Fet Sure style phono pre with MC :)
 
They were "finished" middle of last week, I finally got em from Mike on Friday, had a listen to an A-88, and wasn't really that impressed. But as soon as I got em home into familiar surroundings, I was blown away. At this stage of the build, they are pretty fugly.

Mike's gonna wrap them in Birch veneer, then I'll decide on a proper finish.

Chris, thanks for the excellent instrux on veneering.

my listening comments are being posted as I hear them. These speakers deserve to have the best possible amplifier in front of them. Whether that be class D or tubes or Nelson Pass design, or, or,

The little Icon really is something with these, but as I stated, flattened the image somewhat. Although perfect for a desktop, not perfect in a main system (the Icon). Mike is planning on using them as (large) desktop speakers. We will also remove the OBs from the Spirits, and replace them with the dMar-Kens. This could very well be a very interesting experiment. Personally, I could live happily with either the Jordans or the CHR-70s. But the high value of the CHR-70eNs make it a no brainer. hmmm 2 pairs of CHR-eNs for less than the cost of one pair of Jordans?

I was thinking that a sca-35 re-make or similar would be a great "Nanook Audio" product and could be a complete solution for many. or a Moose preamp/Mos-Fet Sure style phono pre with MC :)


Stew - I really meant - what took you so long to consider trying "some tubes" with the Mark Audio drivers.

enjoy
 
tubes...

all I have here now is my old Phillips console w/external speaker hook up.

My brother has an old Sears Silvertone console he's killing off. He's gonna salvage the receiver and speakers for me. I'd also thought of the SCA35. What I might really like is a HK, Scott, or better yet a Pilot integrated revamped...I just love the cosmetics. Ideally a Leben would be nice (ah, but I'm so poor).

Mike only has the A88, and I have the defunct 300B (still). I guess we should have just left that completely alone, hind sight is 20/20.
 
all I have here now is my old Phillips console w/external speaker hook up.

My brother has an old Sears Silvertone console he's killing off. He's gonna salvage the receiver and speakers for me. I'd also thought of the SCA35. What I might really like is a HK, Scott, or better yet a Pilot integrated revamped...I just love the cosmetics.

The thing about the Dynacos, is that many examples are sufficiently rotted out that a full rebuild is necessary, and if you don't mind eliminating much of the redundant switching, etc., there's room to do some interesting stuff.

Ideally a Leben would be nice (ah, but I'm so poor).
Now that's just too funny - I'd thought about posting a link to the 6moons review of that or the Luxman SQ N100


LUXMAN | PRODUCTS | VACUUM TUBE INTEGRATED AMPLIFIER SQ-N100


An externally hosted image should be here but it was not working when we last tested it.






Mike only has the A88, and I have the defunct 300B (still). I guess we should have just left that completely alone, hind sight is 20/20.
if only we did learn to see these things coming
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.