Stolen Trademark Amplifier from Jim's Audio on EBAY - Page 16 - 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 8th July 2012, 11:34 PM   #151
diyAudio Member
 
Kaplaars's Avatar
 
Join Date: Jul 2010
Location: Wageningen
Aaah, so no luck for you too. But like you wrote, it adds to the fun building a beast like a KSA-100 gives! It is sane to use thermal grease, but I think it is not necessary for this trannies. But, even though the MJE15032/33's will only dissipate about 15 W in total per channel, it does offcourse no harm, so if you have some thermal grease left, I would add it. I used little silicon pads instead, does the same trick. Although, I have to say, the silicon pads conduct heat a bit less than mica + thermal grease. So for the TO-3 devices mica + thermal grease is the best solution (tried for an experiment silicon pads in my class A audio analyse, I could clearly sense the temperature of the TO-3 with silicon pad was higher than the one with mica, so replaced the mica's back).

That is true, you don't need a big heatsink for them. To be fair, I over exaggerated a bit with mine, The heatsink I use is pretty oversized for the task, but I liked the colour
  Reply With Quote
Old 8th July 2012, 11:46 PM   #152
spurlte is offline spurlte  United States
diyAudio Member
 
Join Date: Aug 2011
Quote:
Originally Posted by Kaplaars View Post
Aaah, so no luck for you too. But like you wrote, it adds to the fun building a beast like a KSA-100 gives! It is sane to use thermal grease, but I think it is not necessary for this trannies. But, even though the MJE15032/33's will only dissipate about 15 W in total per channel, it does offcourse no harm, so if you have some thermal grease left, I would add it. I used little silicon pads instead, does the same trick. Although, I have to say, the silicon pads conduct heat a bit less than mica + thermal grease. So for the TO-3 devices mica + thermal grease is the best solution (tried for an experiment silicon pads in my class A audio analyse, I could clearly sense the temperature of the TO-3 with silicon pad was higher than the one with mica, so replaced the mica's back).

That is true, you don't need a big heatsink for them. To be fair, I over exaggerated a bit with mine, The heatsink I use is pretty oversized for the task, but I liked the colour
You seem to be online and will take this opportunity to ask you-what speaker system are you going to use? I am planning to build my speakers as mine are limited to 75w RMS and are quite old-3 way floor speakers. All I need now to finish the Krell are the transformers and can capacitors. Oh, I forgot, a fire extinguisher too.
  Reply With Quote
Old 9th July 2012, 12:18 AM   #153
diyAudio Member
 
Kaplaars's Avatar
 
Join Date: Jul 2010
Location: Wageningen
I have an stereo setup with two B&W DM604 S1 speakers which I will use with the Krell clone when it is finished. They are 4 ohm (3.3 ohm dip), 3 way with two big bass drivers, one kevlar mid and one aluminium tweeter. They can dissipate a maximum of 200W. I really like the sound of B&W. Sound is difficult to describe, but when I have to describe the DM604's they produce that warm, so called English sound. Realy nice and tight bass, nice mids and highs. Although, I have to admit, I miss the 3D stage a bit. Every sound comes from one corner. There are a lot of speakers which I've listen to and do this much more better, but that comes with a price. Like the Piega P10, wow, what a sound. If I ever win the national lotery..... these baby's are mine Well baby's, they are 1,20m!

Don't know in which language this is written, but this link shows a picture of the DM604's I own: http://www.avx.hu/forum/uploads/mont...1307621847.jpg

I have also little B&W DM302's which I use when I test an amplifier. Every time I listen to them I am surprised to the complete sound which these little speakers produce. They won the EISA award back in 1997. Well deserved if you ask me.

Actually, the quality of the speaker is far more important than the amplifier for the sound, since speakers will always be the weakest link. Distortion caused by speakers is much higher than a regular, cheap hifi amplifier will ever have.

It is much fun to compare speakers. Every speaker has another sound. I sometimes go on a trip with my uncle to HiFi stores. Last year we went to Amsterdam comparing speakers. Differences between speakers are far much greater than between amplifiers.

Haha and don't forget to have beer when finishing the Krell to celebrate that it works Spurtle!

Last edited by Kaplaars; 9th July 2012 at 12:21 AM.
  Reply With Quote
Old 9th July 2012, 12:35 AM   #154
spurlte is offline spurlte  United States
diyAudio Member
 
Join Date: Aug 2011
Default Speakers

Quote:
Originally Posted by Kaplaars View Post
I have an stereo setup with two B&W DM604 S1 speakers which I will use with the Krell clone when it is finished. They are 4 ohm (3.3 ohm dip), 3 way with two big bass drivers, one kevlar mid and one aluminium tweeter. They can dissipate a maximum of 200W. I really like the sound of B&W. Sound is difficult to describe, but when I have to describe the DM604's they produce that warm, so called English sound. Realy nice and tight bass, nice mids and highs. Although, I have to admit, I miss the 3D stage a bit. Every sound comes from one corner. There are a lot of speakers which I've listen to and do this much more better, but that comes with a price. Like the Piega P10, wow, what a sound. If I ever win the national lotery..... these baby's are mine Well baby's, they are 1,20m!

Don't know in which language this is written, but this link shows a picture of the DM604's I own: http://www.avx.hu/forum/uploads/mont...1307621847.jpg

I have also little B&W DM302's which I use when I test an amplifier. Every time I listen to them I am surprised to the complete sound which these little speakers produce. They won the EISA award back in 1997. Well deserved if you ask me.

Actually, the quality of the speaker is far more important than the amplifier for the sound, since speakers will always be the weakest link. Distortion caused by speakers is much higher than a regular, cheap hifi amplifier will ever have.

It is much fun to compare speakers. Every speaker has another sound. I sometimes go on a trip with my uncle to HiFi stores. Last year we went to Amsterdam comparing speakers. Differences between speakers are far much greater than between amplifiers.

Haha and don't forget to have beer when finishing the Krell to celebrate that it works Spurtle!
Surprised you are still up and not asleep. It is 7:30PM here in Chicago. Either you're studying or playing around with your Krell. You have a nice week Kaplaars.
  Reply With Quote
Old 9th July 2012, 03:28 AM   #155
spurlte is offline spurlte  United States
diyAudio Member
 
Join Date: Aug 2011
Quote:
Originally Posted by Kaplaars View Post
No problem Zeca ! Nice to see your build is progressing too!!

Made a little bit of progress this evening. In the original Krell there is a little PCB which functions as groundplane. This little groundplane is attached to the cabinet. It also contains two 10 Ohm resistors which are connected between ground and the capacitors. Unfortunatelly I can't make PCB's. Haven't got the chemicals and a little etching tank to oxidise copper into Cu2+ and thus etching nice tracks. But....... Kaplaars is maybe not that old but Kaplaars knows about old school So I scraped little tracks into FR4 (glass loaded epoxy) single sided PCB plate. I coated the copper with some tin. Results could be worse

Click the image to open in full size.

Click the image to open in full size.
What are these groundplanes used for? For what capacitors?
  Reply With Quote
Old 9th July 2012, 06:10 AM   #156
neychi is offline neychi  Croatia
diyAudio Member
 
Join Date: Feb 2005
Location: zagreb
Spurlte, these 10 ohm resistors go between ground and chassis...one for each channel...
__________________
Best Regards

Last edited by neychi; 9th July 2012 at 06:12 AM.
  Reply With Quote
Old 9th July 2012, 10:18 AM   #157
diyAudio Member
 
Kaplaars's Avatar
 
Join Date: Jul 2010
Location: Wageningen
Quote:
Originally Posted by spurlte View Post
Surprised you are still up and not asleep. It is 7:30PM here in Chicago. Either you're studying or playing around with your Krell. You have a nice week Kaplaars.
Haha, well I am a bit like the Djungarian hamster; awake at night It was 2.18 a.m. (I realise right now I mixed a.m. and p.m. up in previous posts) in Holland at that time. But right after that, I got to sleep.

I will use by the way one groundplane. The little one in the picture with the two resistors. In the originall Krell the centertap is not connected directly to the chassis, but there is a resistor in between (R405 in the schematic below).

Click the image to open in full size.

If I understand right the resistor has a function to damp 'mess' that walks into the amplifier via GND. By the way, when making a groundplane you have to choose resistors that can dissipate a few watts, 5 or so, so that is does not function as a fuse when there is short circuit to GND.
  Reply With Quote
Old 9th July 2012, 10:45 AM   #158
spurlte is offline spurlte  United States
diyAudio Member
 
Join Date: Aug 2011
Schematics works so will, doesn't it? "To damp 'mess' that walks in the night. Very well put. So it bring a point I need to resolve. Which ground do you use to shield inputs and outputs? My tube preamp's transformer is not center tapped.
  Reply With Quote
Old 9th July 2012, 12:42 PM   #159
diyAudio Member
 
Join Date: Feb 2009
Quote:
Originally Posted by neychi View Post
Spurlte, these 10 ohm resistors go between ground and chassis...one for each channel...
one are better of using 10ohm NTC, like CL-60 insted of resistors.
  Reply With Quote
Old 9th July 2012, 04:35 PM   #160
diyAudio Member
 
Kaplaars's Avatar
 
Join Date: Jul 2010
Location: Wageningen
Quote:
Originally Posted by spurlte View Post
Schematics works so will, doesn't it? "To damp 'mess' that walks in the night. Very well put. So it bring a point I need to resolve. Which ground do you use to shield inputs and outputs? My tube preamp's transformer is not center tapped.
Yes, creepy nightwalkers are not allowed in my amplifier ;-) Only joking, but the resistors should damp distortion which can travel via GND into your amplifier bit.

I use star ground. All the devices that have to be connected to ground, like the shield around the signalcables, the minus leads of the speaker terminals, earth GND from the wall outlet and so on are connected to the little groundplane. The little groundplane itself is connected to the chassis. So actually all ground leads come together in one point. This is what is called star grounding. Correct grounding is VERY important for a stable, hum free amplifier. Here is some more interesting info: Earthing (Grounding) Your Hi-Fi - Tricks and Techniques
  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
Jim's Audio F5 power supply board Hikari1 Pass Labs 35 4th December 2013 10:41 PM
Jim's Audio Goldmund Telos 390 clone Tyimo Solid State 9 5th March 2013 02:28 AM
Jim's Audio F5 referenced kit. HiVi Guy Pass Labs 21 22nd November 2012 10:24 AM
Stolen items? kctess5 Multi-Way 14 23rd February 2012 10:02 PM


New To Site? Need Help?

All times are GMT. The time now is 12:22 PM.


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