Bogen CHB35a Problem - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

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 March 2010, 05:31 PM   #1
skid20 is offline skid20  United States
diyAudio Member
 
Join Date: Mar 2010
Default Bogen CHB35a Problem

I have a bogen CHB35a that i have had for a few years and finally decided to start a project for the first time.

1. orderd new all new tubes

2. added grounded cord

3. wired mic 1 with 1/4" jack

4. connected 8 ohm speaker plugged up guitar and played for about an hour the first time sounded great nice, clean with lots of power (only took vol to 50% a little at a time over the hour)

5. Second trial same result sounded great no notable bad sounds.

6. removed 70v lead from OT to 3 prong speaker impedance connectors and insulated the end.

7. removed "rem #1" and "rem # 2" leads to screw terminals on back of the chassis leaving all the original resistors in line.

8. removed black/red 25v lead from OT from screw terminal on back of chassis and insulated the end..... According to "S&G Carter" the this lead is supposed to be grounded through a 39k and 10k resistor to ground that was a part of the wiring for the "WMT-1" and "Tape Booster" connectors that are shown in the schematic... only my chassis does not have these connectors and never did, it was just connected strait to the screw terminal on the back of the chassis. I insulated it and that was it.

9. fired the amp back up only to hear a loud hum followed by a high squeal (with vol at 0 ) and no output from the guitar. So I quickly shut off the unit.

Would this have anything at all to do with what I have done here?

I realize the amp needs recapping and could fault at anytime without this being done, and plan to recap to get it back to stock before any serious mods.

I attached a copy of the schematic with the removed items highlighted
Attached Images
File Type: jpg _WEB.jpg (187.2 KB, 49 views)
  Reply With Quote
Old 28th August 2010, 04:09 AM   #2
wonders is offline wonders  United States
diyAudio Member
 
Join Date: Aug 2010
I just finished a Bogen 50 watt and removed the the 70v plugs no sound I cut the ground wire to the plugs and connected to the speaker terminal strip ground , it works great 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
bogen amp karma Tubes / Valves 15 16th August 2011 10:45 PM
Bogen AP35 amp problem Binaural Tubes / Valves 16 16th August 2011 07:29 PM
Help. Bogen m60a Slapdash Tubes / Valves 5 18th January 2008 02:59 PM
Bogen k10 hum problem. stratwrassler Instruments and Amps 1 11th July 2006 05:17 PM
Bogen help sickss Tubes / Valves 0 2nd June 2004 01:25 PM


New To Site? Need Help?

All times are GMT. The time now is 09:26 AM.


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