Salas hotrodded blue DCB1 build - Page 237 - diyAudio
Go Back   Home > Forums > Source & Line > Analog Line Level

Analog Line Level Preamplifiers , Passive Pre-amps, Crossovers, etc.

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 November 2012, 01:39 PM   #2361
diyAudio Member
 
dimkasta's Avatar
 
Join Date: May 2010
Location: Athens
It' s a 40cm x 40cm aluminum plate 5mm thick and with around 3cms bent on the two sides to allow for easier mounting of side walls. It is very nice quality. Heavy and shinny. It even came with a sticky protective sheet on one side to prevent it from getting scratched.

I was planning to use them on my F5 monoblocks, but I always get some surplus

Click the image to open in full size.
  Reply With Quote
Old 13th November 2012, 07:18 PM   #2362
diyAudio Member
 
dimkasta's Avatar
 
Join Date: May 2010
Location: Athens
OK as promised here are some more photos from the current status

Here is the board with the 5x5R @5W resistors attached in parallel to the 10R Mills.

Click the image to open in full size.

You can also see the additional heatsinks just thrown in there not firmly attached. The two bigger ones will go to left and right, and the two smaller ones will go top and bottom.
I also got two additional ones (you can see part of them on the right on the floor) that will go to the bottom of the plate and be attached using the same screws with the fets.

And here is another one with the lights on as it is now. Replaced the resistors with 1R @10W. Those still get pretty hot though....

Click the image to open in full size.

Current measurements are
CCS resistance ~0R9
CCS current ~1,2A

With the single resistors and after hearing a song or two, I believe the thinness was fixed a bit. Still pretty early to make any serious comments with the freshly soldered parts. Anyway. just do not do any critical listening with chunks of cement resistors attached.
Attached Images
File Type: jpg DIM_1257.jpg (243.4 KB, 454 views)
File Type: jpg DIM_1258.jpg (239.5 KB, 451 views)
  Reply With Quote
Old 13th November 2012, 08:01 PM   #2363
diyAudio Member
 
dimkasta's Avatar
 
Join Date: May 2010
Location: Athens
Quick question. How hot are the 1R resistors supposed to run? The 10W ones I have, got pretty hot quickly. An hour later they were at around 70C
  Reply With Quote
Old 13th November 2012, 08:05 PM   #2364
Tea-Bag is offline Tea-Bag  United States
not politcally affiliated
diyAudio Member
 
Tea-Bag's Avatar
 
Join Date: Feb 2006
Location: Kennebunk
Blog Entries: 7
Quote:
Originally Posted by dimkasta View Post
Quick question. How hot are the 1R resistors supposed to run? The 10W ones I have, got pretty hot quickly. An hour later they were at around 70C
In your situation, I would read the spec sheet for that resistor from that vendor.
70c for a power resistor is usually okay.
__________________
Salas Boards 2014 #2 On order |F5TC board and power supplies available PM | Hot-Rod DCB1 boards and kits available PM |Mesmerize kits available (no boards)
  Reply With Quote
Old 13th November 2012, 08:31 PM   #2365
diyAudio Member
 
dimkasta's Avatar
 
Join Date: May 2010
Location: Athens
I doubt there is such a thing. Even if I knew the vendor. They are just unbranded plain cheap blocks bought from a local shop.
  Reply With Quote
Old 13th November 2012, 08:42 PM   #2366
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Nominal resistor power when it is at least 3x the actual power dissipated keeps an honestly characterized resistor safe in the long run. Ventilation and orientation come into play too. There is a chart in well documented types that shows the derating with rising temp.
  Reply With Quote
Old 13th November 2012, 10:03 PM   #2367
diyAudio Member
 
dimkasta's Avatar
 
Join Date: May 2010
Location: Athens
So is it normal to have ~70C in those with only ~1,2W ?

If so it' s also not a good idea to keep them so close to the filter caps too
  Reply With Quote
Old 14th November 2012, 04:35 AM   #2368
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Its 12W actually when having 1.2A through and 10V across each. 70C on the internal silicone die is safe. That means 50C on their cases you stick the thermocouple at in your config. For capacitors you gain life time inversely proportional to the ambient they live in. Double their half rated lifetime for each 10C less than their temp rating and add it up.
  Reply With Quote
Old 14th November 2012, 07:36 AM   #2369
diyAudio Member
 
dimkasta's Avatar
 
Join Date: May 2010
Location: Athens
Quote:
Originally Posted by Salas View Post
Its 12W actually when having 1.2A through and 10V across each.
Isn't it 1,2V across them?
  Reply With Quote
Old 14th November 2012, 08:40 AM   #2370
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
No, its whatever your transfo and bridge gives minus Vout across the CCS one (drain to source) and Vout (~10V) across the output one. For your setting resistor its dissipation is its voltage drop times what it runs. 1.2A now.
  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
dcb1 buffer with shunt reg. merlin2069er Swap Meet 0 3rd August 2010 05:25 PM
F2 and DCB1 parts selection - please advice! DQ Pass Labs 6 25th November 2009 03:20 PM
Y B Blue - how blue LED improves the CD playback Peter Daniel Digital Source 176 25th September 2003 07:40 AM


New To Site? Need Help?

All times are GMT. The time now is 04:12 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