+8
pedrocols
vtshopdog
LeGrace
Dahlberg
Roy Mottram
aguaazul
Kentley
GP49
12 posters
My KT120 / M-125's
Dahlberg- Posts : 132
Join date : 2016-09-27
Age : 62
Location : Sweden
- Post n°26
Re: My KT120 / M-125's
It's coming along
LeGrace- Posts : 388
Join date : 2016-08-07
Location : Ontario, Canada
- Post n°27
Re: My KT120 / M-125's
Love your carpentry skills!
Dahlberg- Posts : 132
Join date : 2016-09-27
Age : 62
Location : Sweden
- Post n°28
Re: My KT120 / M-125's
Thanks, some decent tools helps a lot I decided on a very simple profile and
just added a 45° angle over the corners to make them a bit more durable.
just added a 45° angle over the corners to make them a bit more durable.
LeGrace- Posts : 388
Join date : 2016-08-07
Location : Ontario, Canada
- Post n°29
Re: My KT120 / M-125's
Dahlberg wrote:Thanks, some decent tools helps a lot I decided on a very simple profile and
just added a 45° angle over the corners to make them a bit more durable.
My attempt at doing mitered corners was a total fail. Yours look amazing!
Dahlberg- Posts : 132
Join date : 2016-09-27
Age : 62
Location : Sweden
- Post n°30
Re: My KT120 / M-125's
Well without the tools it just doesn't work. Hard enough with them.
Dahlberg- Posts : 132
Join date : 2016-09-27
Age : 62
Location : Sweden
- Post n°31
Re: My KT120 / M-125's
This is my dsp xo, no mitred corners and usually turns out good looking.
Kentley- Posts : 496
Join date : 2015-03-06
Age : 71
Location : Worcester, MA
- Post n°32
Re: My KT120 / M-125's
That is simply stunning, sir. The wood knob is superb. All my hats are off. I'm running out of hats.
Dahlberg- Posts : 132
Join date : 2016-09-27
Age : 62
Location : Sweden
- Post n°33
Re: My KT120 / M-125's
Thanks. To bad I have to build a new one The first one has two hardwired "Unballancers" but
I'm rebuilding for tubes on all outputs using the pcb's from John Broskie.
Then there is just not enough space. The sub output is opamp based today and I also had
the possibility to run a second identical opamp buffer for mid bass for a while, but the
"Unballancer" came out such a strong solution that I decided to use that for the sub region as well.
It's all based around the "Najda" dsp and three separate "BuffaloIII" dacs.
Twisted pear is releasing the "BuffaloIV" using the new "Ess 9038pro" chip in the hopefully not
so distant future and I'm waiting for the 8-channel version of that dac, the project is on
a stand still for now. The surprisingly strong result from the output buffer shootout was one of
the reasons that I decided to try a tube power amp solution in that region as well.
It's not possible for the sub section though.
Edit: Picture
I'm rebuilding for tubes on all outputs using the pcb's from John Broskie.
Then there is just not enough space. The sub output is opamp based today and I also had
the possibility to run a second identical opamp buffer for mid bass for a while, but the
"Unballancer" came out such a strong solution that I decided to use that for the sub region as well.
It's all based around the "Najda" dsp and three separate "BuffaloIII" dacs.
Twisted pear is releasing the "BuffaloIV" using the new "Ess 9038pro" chip in the hopefully not
so distant future and I'm waiting for the 8-channel version of that dac, the project is on
a stand still for now. The surprisingly strong result from the output buffer shootout was one of
the reasons that I decided to try a tube power amp solution in that region as well.
It's not possible for the sub section though.
Edit: Picture
aguaazul- Posts : 136
Join date : 2012-07-08
Age : 63
Location : Livermore, CA
- Post n°34
Re: My KT120 / M-125's
Looking good all around! I'd be interested in looking at the full build history on your DAC solutions if you don't mind sharing.
Cheers,
Blue
Cheers,
Blue
Dahlberg- Posts : 132
Join date : 2016-09-27
Age : 62
Location : Sweden
- Post n°35
Re: My KT120 / M-125's
aguaazul wrote:Looking good all around! I'd be interested in looking at the full build history on your DAC solutions if you don't mind sharing.
Cheers,
Blue
If you do a Google picture search for "najda dahlberg dsp" you will find most of the
information (at diyaudio). The "Najda thread" is a bit hard to read through (300+ pages)
but with the pictures to go from you would start at the more relevant pages.
For information about the new solution a good place to start would be the unbalancer manual.
http://glass-ware.com/User_Guides/Unbalancer%209-pin%20-PS.pdf
The "BuffaloIV" doesn't exist yet but the "buffaloIIIse" is what I have been using up till now.
http://twistedpearaudio.com/digital/buffalose.aspx
And since this is a picture thread about the M-125
LeGrace- Posts : 388
Join date : 2016-08-07
Location : Ontario, Canada
- Post n°36
Re: My KT120 / M-125's
Mad wiring skills
Dahlberg- Posts : 132
Join date : 2016-09-27
Age : 62
Location : Sweden
- Post n°37
Re: My KT120 / M-125's
Don't know about that, but hopefully it will work when it's done.
Roy Mottram- Admin
- Posts : 1840
Join date : 2008-11-30
- Post n°38
Re: My KT120 / M-125's
I tend to keep my oven around 200-225 to cure paint, not any higher, and usually 15-20 minutes is plenty
Dahlberg- Posts : 132
Join date : 2016-09-27
Age : 62
Location : Sweden
- Post n°39
Re: My KT120 / M-125's
Well the next time I will use spraypaint I will be more careful with temperature. Bad news about the powder coating as well.
The "candy gold" didn't turn out good at all and the paintguy thought it was a problem with the powder itself.
So now there is a new colour in the making. Candy red this time, a quite dark one.
The "candy gold" didn't turn out good at all and the paintguy thought it was a problem with the powder itself.
So now there is a new colour in the making. Candy red this time, a quite dark one.
Last edited by Dahlberg on Thu Nov 17, 2016 9:36 am; edited 1 time in total
Dahlberg- Posts : 132
Join date : 2016-09-27
Age : 62
Location : Sweden
- Post n°41
Re: My KT120 / M-125's
I could not help myself so I had to see how it looked with tubes in place. It turns out a bit lighter on camera then it looks.
LeGrace- Posts : 388
Join date : 2016-08-07
Location : Ontario, Canada
- Post n°42
Re: My KT120 / M-125's
Stunning! What did you do with the power switch? Have you considered brass plaques for the front?
Dahlberg- Posts : 132
Join date : 2016-09-27
Age : 62
Location : Sweden
- Post n°43
Re: My KT120 / M-125's
The power switch is on the back, you can see part of it on an earlier picture. I'm not planning for any brass plaque, hmmm.
Dahlberg- Posts : 132
Join date : 2016-09-27
Age : 62
Location : Sweden
- Post n°44
Re: My KT120 / M-125's
Got them fired up yesterday, and got some slight hum. Trying a screened feedback cable today to see if that solves it. Got a tip at diyaudio from a Canadian guy who had the same issue, apart from that it was a rawing review Mine sounds promising
vtshopdog- Posts : 155
Join date : 2015-07-11
Location : UT, USA
- Post n°45
Re: My KT120 / M-125's
Dahlberg wrote:Got them fired up yesterday, and got some slight hum. Trying a screened feedback cable today to see if that solves it. Got a tip at diyaudio from a Canadian guy who had the same issue, apart from that it was a raving review Mine sounds promising
Do I understand correctly that you are replacing the yellow(usually?) wire that runs from the O.T. to PCB with a splice of shielded cable?
Beautiful build BTW
Dahlberg- Posts : 132
Join date : 2016-09-27
Age : 62
Location : Sweden
- Post n°46
Re: My KT120 / M-125's
vtshopdog wrote:Dahlberg wrote:Got them fired up yesterday, and got some slight hum. Trying a screened feedback cable today to see if that solves it. Got a tip at diyaudio from a Canadian guy who had the same issue, apart from that it was a raving review Mine sounds promising
Do I understand correctly that you are replacing the yellow(usually?) wire that runs from the O.T. to PCB with a splice of shielded cable?
Beautiful build BTW
Thanks
Yes it's the yellow one. I cut it short just leaving a few centimeters for connetion to a screened
cable that I connected to the pcb. The screen is only connected to ground at the input board.
I'm using twisted wire for the line level input, maybe a screened cable would be an idea there as well
So first initial listening impression
I really like the synergy they create with my 300b amps. Everything just seems to fit better together
resulting in a more relaxed and natural listening experience. I have a gain structure that is based
on the possibility to go to full blast without distroying anything and full blast now feels less loud (less distortion?).
Wood intruments and percusion sounds more natural, the lower notes on saxophone are just fenomenal.
Dynamics are at least as good as earlier or even better, I'm leaning to the second on that.
For now the only thing that could use some attention is the lowest bass region, where they leave over to
the subs. It seems that I have lost some definition in that area. Maybe another rectifier solution and also try the 8 ohm tap ?
I'm only using them from 65-350hz.
Dahlberg- Posts : 132
Join date : 2016-09-27
Age : 62
Location : Sweden
- Post n°47
Re: My KT120 / M-125's
There are some small adjustments left but it's slowly coming in to place
Dahlberg- Posts : 132
Join date : 2016-09-27
Age : 62
Location : Sweden
- Post n°48
Re: My KT120 / M-125's
So now the feedback wire is relocated as described in the picture and I
measured less than 2,0 mV ac of the speaker connections. This amp is very quiet.
Only difference is that in my amps the wire comes closer to the bottom of the cabinet.
Thanks to Bob and some other guy at DIYAUDIO for pointing this out.
measured less than 2,0 mV ac of the speaker connections. This amp is very quiet.
Only difference is that in my amps the wire comes closer to the bottom of the cabinet.
Thanks to Bob and some other guy at DIYAUDIO for pointing this out.
pedrocols- Posts : 162
Join date : 2014-11-24
Location : Western MA
- Post n°49
Re: My KT120 / M-125's
Very nice! I have mine for a little over two years now and still running strong. I suspect I will have to shortly get some new tubes.
Dahlberg- Posts : 132
Join date : 2016-09-27
Age : 62
Location : Sweden
- Post n°50
Re: My KT120 / M-125's
Thanks, I'm doing some evaluation regarding what output tap to use. Tomorrow.
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