jajabin said:
I believe that the BOM for the kit buy is from Jan's website www.delta-audio.com. It should be the same for both boards. PinkMouse had posted a BOM from his proto as well with some substitutions about 20 pages back.
~Brad
jajabin
If you didn't found it already, here is Al's BOM.
Pinkmouse BOM
OK, in case some of you start missing me, I'm going to try to install my wireless network now.
Cheers
If you didn't found it already, here is Al's BOM.
Pinkmouse BOM
OK, in case some of you start missing me, I'm going to try to install my wireless network now.
Cheers
Krell Clone Activated
We Have iginition.
Before I post a lot of pics ..... I just want to say thank you to Stewart and Jacco
for helping me with this tough project.
And also thanks to
everyone else including Terry for your comments, kind of forget who said what.
This project was not easy.
Right now, this is running about 20W class A in "low" bias mode
and slightly over 50W in "high" bias mode. Sound is great,
square wave response is awesome. Its 2:21 am and I've got
over 1200 songs left on the ipod! In "high" bias mode I get
about 63 degrees C on the output heat sinks, with the 2 fans
turned down so that they don't mae a lot of noise.
Man, setting bias is time consuming, I'm going to run down the
battery in my DMM. I've been running this since 12 and as things
heat up bias is unpredictable. I'm withing .01 V on bias between
channels but trying to do better
DC offset is .02 to .03 per channel, and I can't adjust this since in
my "chassis" a lot of stuff is not reachable.
We Have iginition.
An externally hosted image should be here but it was not working when we last tested it.
Before I post a lot of pics ..... I just want to say thank you to Stewart and Jacco
for helping me with this tough project.
And also thanks to
everyone else including Terry for your comments, kind of forget who said what.
This project was not easy.
Right now, this is running about 20W class A in "low" bias mode
and slightly over 50W in "high" bias mode. Sound is great,
square wave response is awesome. Its 2:21 am and I've got
over 1200 songs left on the ipod! In "high" bias mode I get
about 63 degrees C on the output heat sinks, with the 2 fans
turned down so that they don't mae a lot of noise.
Man, setting bias is time consuming, I'm going to run down the
battery in my DMM. I've been running this since 12 and as things
heat up bias is unpredictable. I'm withing .01 V on bias between
channels but trying to do better
DC offset is .02 to .03 per channel, and I can't adjust this since in
my "chassis" a lot of stuff is not reachable.
1 more
Here is 1 more.
You see how I borrowed the old and the new from the K company. A triangle of lights indicates + and - voltage and (the top one) that sofstart has been accomplished as the delayed relay control voltage to bypass the CL-60 thermisters is active.
Aerogate 3 fan controller (from my parts box...yeah right...) gives speed control of 4 fans (2 in the clone) and temp readout of 4 zones. I'm monitoring (1 and 2) temp of output stage heatsinks (2 rails on 2 channels), (3) heat sink of driver and (4) heat sink of volt. regulator.
Solid black walnut, as with the other stuff I have made, all wood panels are bolted to the chassis with 10-32 hex bolts including the bottom plate which has adjustable feet. You see steel shielding plates painted yellow, only because cold rolled steel looks really lousy.
This is huge, weighs a ton also. Its 18" deep, 13.5" wide (at base) and 15" tall. Weight to be posted later.
This is the bad side with a scratch. Other side was done 2nd and is flawless. I learned from my errors with the Fostner bit on this side. See my web page (link below).
Will post a general description in "solid state" here tomorrow, I know there are some posts pending here which I don't want to interrupt.
Here is 1 more.
You see how I borrowed the old and the new from the K company. A triangle of lights indicates + and - voltage and (the top one) that sofstart has been accomplished as the delayed relay control voltage to bypass the CL-60 thermisters is active.
Aerogate 3 fan controller (from my parts box...yeah right...) gives speed control of 4 fans (2 in the clone) and temp readout of 4 zones. I'm monitoring (1 and 2) temp of output stage heatsinks (2 rails on 2 channels), (3) heat sink of driver and (4) heat sink of volt. regulator.
Solid black walnut, as with the other stuff I have made, all wood panels are bolted to the chassis with 10-32 hex bolts including the bottom plate which has adjustable feet. You see steel shielding plates painted yellow, only because cold rolled steel looks really lousy.
This is huge, weighs a ton also. Its 18" deep, 13.5" wide (at base) and 15" tall. Weight to be posted later.
This is the bad side with a scratch. Other side was done 2nd and is flawless. I learned from my errors with the Fostner bit on this side. See my web page (link below).
Will post a general description in "solid state" here tomorrow, I know there are some posts pending here which I don't want to interrupt.
Upupa Epops said:And look inside ?
I really don't know how you guys do it with the neat wiring and layout. I've planned out the chassis and layout for about 8 months but still it looks like the old birds nest. But at least I drilled a lot of holes and "channels" to pass wires back and forth.
With a detached output stage you need a lot of connectors, I used shielded wire and grounded the destination shield. Yet still you see a TON of those crimp connectors. I actually came close to using a package of 100.
Better views of the interals will be forthcoming. You cannot see the fan below the heatsinks and many other items.
Got to say that it sounds great, no problems with soundstage or channel separation which I measured. No hiss or hum problems at all. Not sure if I was supposed to connect speaker ground to star ground (I did) or from caps to output (I did not).
I admit it, I'm a hack. And I love it. No apologies.
Side view.
(The softstart board on the bench goes above the caps and dual transformers. )
An externally hosted image should be here but it was not working when we last tested it.
Front view during testing.
An externally hosted image should be here but it was not working when we last tested it.
You see the green LEDs I discussed at post #3532 shining bright -- indicating that I am not "green" at the present time - - its "high bias" time. The "2610 RPM" indicates the measured RPM of the bottom fan. I like my eqipment to give as much status info as possible. Here I get RPM of both fans, 4 temps, and an alarm if a preset temp goes to high, plus voltage on 2 rails (front LEDs.) Nice stuff, which I put in bias meters. ....
Mr. Green
Just visited your website and looked at the KSA50 page. I noticed a picture of the backside of the driverboards with some mods on it. Can you tell us what's the purpose of the green wire and those two resistors are?
http://www.parttimeprojects.com/audio/diy/Images/Krell Clone/36_inputnew2.jpg
Best regards
Just visited your website and looked at the KSA50 page. I noticed a picture of the backside of the driverboards with some mods on it. Can you tell us what's the purpose of the green wire and those two resistors are?
http://www.parttimeprojects.com/audio/diy/Images/Krell Clone/36_inputnew2.jpg
Best regards
green wire
Hmmm.... I think that green wire connects the distal end of the green LED to ground, where the other end is connected through 3.0K and .9K to +VCC. Recall that I installed a switch and 2nd trimpot for "high" bias, as well as an LED.
Conviently, I used the unused junction I think between D303 and D304 or D305 and D306 which are not connected to anything else but each other. So one leg goes to ground and the other goes to + VCC through these 2 resistors you see.
At least this is what I think that is showing...
Did you see the back panel? I've got a multipin output connector connected with 4 pins across 2 emitter resistors for setting bias. I was wondering why I could not find a mating connector till I realized that the connector I used was probably a TUBE socket. Doh!
As I said, I'm still a hack. You know I look at the pics and see "up" with an arrow. I drilled the holes in the side panels with that pointed "down" and you know what-- it fit better when I turned it around like it should have been. From the electrical to the mechanical, I'm lucky I don't have more problems. But don't kid yourself-- I've got a lot of problems; took me 3 hours this morning to debug a working left channel that had 0.0 voltage across the emitter resistors. Turns out Vout + was connected to Vin - and vice-versa. Would have taken less time except that output on the scope looked perfect.
Hmmm.... I think that green wire connects the distal end of the green LED to ground, where the other end is connected through 3.0K and .9K to +VCC. Recall that I installed a switch and 2nd trimpot for "high" bias, as well as an LED.
Conviently, I used the unused junction I think between D303 and D304 or D305 and D306 which are not connected to anything else but each other. So one leg goes to ground and the other goes to + VCC through these 2 resistors you see.
At least this is what I think that is showing...
Did you see the back panel? I've got a multipin output connector connected with 4 pins across 2 emitter resistors for setting bias. I was wondering why I could not find a mating connector till I realized that the connector I used was probably a TUBE socket. Doh!
As I said, I'm still a hack. You know I look at the pics and see "up" with an arrow. I drilled the holes in the side panels with that pointed "down" and you know what-- it fit better when I turned it around like it should have been. From the electrical to the mechanical, I'm lucky I don't have more problems. But don't kid yourself-- I've got a lot of problems; took me 3 hours this morning to debug a working left channel that had 0.0 voltage across the emitter resistors. Turns out Vout + was connected to Vin - and vice-versa. Would have taken less time except that output on the scope looked perfect.
hacking
Chassis was bought surplus with the heat sinks when the board was 1st being designed....the 1st time. The entire amp was built around these $35.00 components. See Mystery Amp link.
Put some nice wood side panels on anything and it will look great. For some reason I started doing this and I guess its a feature of my stuff.
People should recognize the horrible problems with a unique case. I spent 30 minutes trying to find a washer I dropped in the case and could not take it apart because I would have to disconnect major circuitry. I've got vertical sections, threaded elbows, holes with epoxy to prevent wire chaffing, all kinds of crazy stuff. A flat, wide and deep chassis with heatsinks cannot be beat for ease of construction. This was a nightmare even tough the case was very easy to work with.
The case is great, every panel comes off independent of every other panel-- until you put on the final faceplate. Then nothing except the top (and back) can come off. For this amp, because I cover the existing front panel coutout with my own front panel (which for some reason I did not thread the mounting holes for) the entire thing has to be put together in a unique sequence with wierd steps involving double stick tape and yardsticks (for the two front panel bolts on the bottom which are inaccessible). But i digress...
jacco vermeulen said:
Chassis was bought surplus with the heat sinks when the board was 1st being designed....the 1st time. The entire amp was built around these $35.00 components. See Mystery Amp link.
Put some nice wood side panels on anything and it will look great. For some reason I started doing this and I guess its a feature of my stuff.
People should recognize the horrible problems with a unique case. I spent 30 minutes trying to find a washer I dropped in the case and could not take it apart because I would have to disconnect major circuitry. I've got vertical sections, threaded elbows, holes with epoxy to prevent wire chaffing, all kinds of crazy stuff. A flat, wide and deep chassis with heatsinks cannot be beat for ease of construction. This was a nightmare even tough the case was very easy to work with.
The case is great, every panel comes off independent of every other panel-- until you put on the final faceplate. Then nothing except the top (and back) can come off. For this amp, because I cover the existing front panel coutout with my own front panel (which for some reason I did not thread the mounting holes for) the entire thing has to be put together in a unique sequence with wierd steps involving double stick tape and yardsticks (for the two front panel bolts on the bottom which are inaccessible). But i digress...
pinkmouse said:
Well, it seems now that I haven't. It seemed to be working fine. The only thing that bothered me was that when I plugged in the preamp , I had a slight hum. Only when both sides were plugged in. If I only had one channel plugged in, no hum. I found if I unhooked the ground for either board then the hum would disappear, So I just disconnect the ground from both boards and only had the speaker grounds and the CT from the transformer attached to the CT of the filter cap ground plain. Seemed to work fine so I let it play all day yesterday as I worked around cleaning things up. Started and stopped in several times throughout the day as I listened back and forth between it and the P101 to try and get a picture of how they compared. Well, last night, when I turned it off, I heard that growl as it shut down. Hooked up the meter and switched it back on and sure enough, there's that huge offset again. Like 28VDC at fire up for about 5 seconds and then everything settles back down.
I'm heading to church. I will have to deal with this when I get back. I'm pretty puzzled right now. It sure seemed like I had it licked. I have this exact same CRC setup in my P101 running at 67VDC for the last few months with no problems what-so-ever.
I tried bypassing the resistors on the CRC and no change. I don't really know how to check the caps to see if another one failed. I have some large caps that I can hook up instead to see but if there is something wrong that is destroying them, I'd rather not. If you guys have some ideas as to were to look next, I'm all ears.
Blessings, Terry