Simple SE power transfomer question? - Page 2 - diyAudio
Go Back   Home > Forums > Commercial Sector > Vendor Forums > Tubelab

Tubelab Discussion and support of Tubelab products, prototypes and experiments

Reply
 
Thread Tools Search this Thread
Old 7th March 2010, 07:30 PM   #11
diyAudio Member
 
Ty_Bower's Avatar
 
Join Date: Mar 2007
Location: Newark, DE
Geez, Russ, you do nice work!
  Reply With Quote
Old 7th March 2010, 07:40 PM   #12
rknize is offline rknize  United States
diyAudio Member
 
rknize's Avatar
 
Join Date: Feb 2009
Location: Chicagoland
Send a message via AIM to rknize Send a message via Yahoo to rknize
Thanks Ty! It's more about being really anal. I put binding posts there, but I knew full well that I would probably almost never swap the resistor because it means flipping the amp over and opening it up. I'm just too lazy, LOL...
  Reply With Quote
Old 17th March 2010, 08:07 PM   #13
ryc989 is offline ryc989  United States
diyAudio Member
 
Join Date: Feb 2010
Default My Board Pictures

Hi,

I just wanted to post a few pictures of my board, I ordered my output iron and will have to wait 4 to 6 weeks for it to arrive. I might order a set of small Edcor output transformers so I can test my setup and order my simple pp power transformer at the same time since that is my next project.

Regards
Attached Images
File Type: jpg Picture 001a.jpg (207.6 KB, 229 views)
File Type: jpg Picture 002a.jpg (209.4 KB, 216 views)
  Reply With Quote
Old 17th March 2010, 09:08 PM   #14
rknize is offline rknize  United States
diyAudio Member
 
rknize's Avatar
 
Join Date: Feb 2009
Location: Chicagoland
Send a message via AIM to rknize Send a message via Yahoo to rknize
Looks like it's ready to rock.
  Reply With Quote
Old 3rd April 2010, 06:07 PM   #15
ryc989 is offline ryc989  United States
diyAudio Member
 
Join Date: Feb 2010
Default My Simple PP Board

Hi,

Since I am waiting for iron for both my projects I decided to build my simple PP board. I have attached pictures, the board is very heavy once finished, btw, ! I guess I will move onto building the chassis for both my simple SE and simple PP projects and will attach pictures as I make further progress. One note, the space for the coupling caps got very tight. I think that some thought needs to go into the size of caps being chosen, I used caps that I feel will give me the sonic results I want, i.e. transparency and little sonic signature. I had some challenges getting them in place and keeping the leads away from several of the tube socket pads. Just a heads up to other people who will be building this project.

Regards
Attached Images
File Type: jpg Picture 007a.jpg (248.9 KB, 175 views)
File Type: jpg Picture 006a.jpg (194.9 KB, 148 views)
  Reply With Quote
Old 16th April 2010, 05:46 PM   #16
ryc989 is offline ryc989  United States
diyAudio Member
 
Join Date: Feb 2010
Question Amp check out

Hi,

I was doing the checkout on my amp and after a Kodak moment and realizing that I was using AC instead of DC to check the voltages everything appears to be ok?? I just have a few questions:

If I ohm out the primary side of my output transformers should I see a 5K resistance?
I am measuring about 380 ohms and the UL tap is about 160 ohms. Also, when measuring across the output of the transformer I only see a little over 1 ohm??

The reason for asking is when checking out the amp with audio in, I was able to get sound and the volume level seemed ok, just the sound was a little muffled?? I am also not sure that the tubes were not running some what hot?? I am using a 1k resistor for R17 and R27. I am just wondering if there isn't some issue with the output transformers?? I tried both 6L6 and EL34 tubes, although the EL34 tubes seemed to glow overly bright , so I just shut the amp down.

Regards
  Reply With Quote
Old 16th April 2010, 05:59 PM   #17
rknize is offline rknize  United States
diyAudio Member
 
rknize's Avatar
 
Join Date: Feb 2009
Location: Chicagoland
Send a message via AIM to rknize Send a message via Yahoo to rknize
Quote:
Originally Posted by ryc989 View Post
If I ohm out the primary side of my output transformers should I see a 5K resistance?
I am measuring about 380 ohms and the UL tap is about 160 ohms. Also, when measuring across the output of the transformer I only see a little over 1 ohm??
That sounds about right. 5k is the primary's AC impedance, which is not the same thing as the DC resistance (what you are measuring with your meter). If you want to know more about AC impedance and why it ends up having units of ohms, there are lots of sources on the Internet and books.

Quote:
The reason for asking is when checking out the amp with audio in, I was able to get sound and the volume level seemed ok, just the sound was a little muffled?? I am also not sure that the tubes were not running some what hot?? I am using a 1k resistor for R17 and R27. I am just wondering if there isn't some issue with the output transformers?? I tried both 6L6 and EL34 tubes, although the EL34 tubes seemed to glow overly bright , so I just shut the amp down.
What was glowing? The plates or the filaments? 1k is a little soft for a cathode resistor and might explain your weak output. Next time you power it up, take some voltage measurements.

1) B+ This is the voltage (from ground) at R1, R4, C2, R14, R24, and the red wire of your OPT.

2) Across R17 or R27 (one meter probe on each leg of the resistor). This is the output tube bias voltage.

3) Across R13 or R23. From this we can measure the input/driver tube plate current.

Also, some pictures of your wiring might be helpful.
  Reply With Quote
Old 17th April 2010, 12:01 AM   #18
ryc989 is offline ryc989  United States
diyAudio Member
 
Join Date: Feb 2010
Default Listening to it!

Hi,

Thank you for the reply so here are the voltages I measured(all DC measurements):
no R1 have choke but 487v
R4 487v
C2 487v
on one side of R14 400V - 397V fluctuates a little the other side 487v
on one side of R24 398V - 396V fluctuates a little the other side 487v
across R17 45v
across R27 45v
across R13 2.88v
across R23 2.88v

I picked the value of 1K based on the output transformers I will eventually use, rated for 60ma. I have purchased a set of transcendar opt's to use to test this amp, they are rated for 90ma. The 45v is what I was expecting or looking for I believe, 45v/1000ohms = .045a = 45ma I have re-checked everything and I am using a better pair of speakers now. I am using the diodes as a rectifier as the only 5AR4 tube I have currently is way to valuable to risk. I have ordered some new 5AR4 tubes and will use them once they arrive. The amp actually plays more than loud enough for me. I am using a preamp and my only source is vinyl and my first impressions now are the sound is good(bass is different!). I am using $4 Chinese 6L6 tubes (eBay special,I am going to try my $4 EL34's next!) so I am not sure how good the sound will or will not be but I just want to make sure everything works for now. I know the pictures look like they came out of a 50's 'B" horror movie, but I am going to reuse this setup for my simple pp amp once this project is complete. I really do appreciate all the help and support here, I do not think I could find a better place or group of people to build a project with!

Regards
Attached Images
File Type: jpg Picture 013a.jpg (295.7 KB, 120 views)
File Type: jpg Picture 012a.jpg (311.3 KB, 60 views)
File Type: jpg Picture 011a.jpg (237.6 KB, 56 views)
  Reply With Quote
Old 17th April 2010, 02:25 AM   #19
rknize is offline rknize  United States
diyAudio Member
 
rknize's Avatar
 
Join Date: Feb 2009
Location: Chicagoland
Send a message via AIM to rknize Send a message via Yahoo to rknize
Everything looks good based on your setup. Your B+ is fairly high right now...a combination of the Hammond and using the SS diodes. With the 5AR4 in there, the tube drop plus the extra load from the 5V heater will bring it down some. The 6L6 is running in a region that is not as linear as it could be if it were run with a lower Vgk. Take a look at the triode curves for the 6L6GC and you will see what I mean. I would pick up a couple of other sets of cathode resistors if you haven't already. They are cheap and it makes it worth experimenting.
  Reply With Quote
Old 17th April 2010, 02:30 AM   #20
diyAudio Member
 
Ty_Bower's Avatar
 
Join Date: Mar 2007
Location: Newark, DE
Your voltages look perfect. Each half of the 12AT7 is drawing 8.7mA, which is where it should be. The power tubes, drawing 45mA each, are dissipating a total of 19.9 watts. I'd figure that's pretty much ideal. The Transcendar output transformers are pretty good performers. I have a set of his 5K:8 in my Simple SE and I'm extremely pleased with them.
  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
Simple SE C11/C21 Question BillEpstein Tubelab 6 30th January 2010 03:08 PM
Question for B+ in Simple SE cgian Tubelab 8 27th January 2010 05:17 PM
Simple SE Grounding Question SGregory Tubes / Valves 2 17th November 2009 11:35 AM
simple se cathode resistor question pforeman Tubes / Valves 4 1st June 2009 05:08 PM
Another simple se question newtube Tubelab 5 18th May 2009 08:55 PM


New To Site? Need Help?

All times are GMT. The time now is 01:38 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