Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: dpm309 on September 23, 2017, 02:28:59 pm

Title: Blues Jr. Reverb Problem
Post by: dpm309 on September 23, 2017, 02:28:59 pm
Trying to get the reverb working on a Blues Jr. Measured the resistance on the input side and am getting about 700 ohms but on the output side, I am getting no continuity. Removed the tank and noticed 2 wires broke off the end of the springs on the output side. Rewired it and am still not getting any continuity. The tank is numbered 8EB2C1B. Plugged in the reverb tank from my revibe unit (9AB3C1B) and am only getting a distorted sound when I turn up the reverb control. Would this be caused by using a different reverb tank in the BJ? Or am I looking at something wrong with the reverb circuit. Checked the resistors and diode associated with the reverb circuit and can't find anything wrong. Am getting -16V on the anode side of D14. This is the Blues Jr. Rev A cream board version. I attached a copy of the schematic which is hard to read but the only copy I can find.
Any suggestions?
Thanks
Title: Re: Blues Jr. Reverb Problem
Post by: sluckey on September 23, 2017, 02:37:06 pm
Your revibe tank won't work with the BJ circuit. Get a proper replacement tank. AES has it...

     https://www.tubesandmore.com/search/node/8EB2C1B (https://www.tubesandmore.com/search/node/8EB2C1B)
Title: Re: Blues Jr. Reverb Problem
Post by: dpm309 on September 23, 2017, 02:56:22 pm
That is what I suspected. Will go ahead order one.
Thanks
Title: Re: Blues Jr. Reverb Problem
Post by: dpm309 on September 24, 2017, 10:25:27 am
Are there any major differences between the 3 8EB2C1B reverb tanks from AES? The Belton and Fender MOD tanks are a few dollars less. I read on Bill M's website that the wires in Acutronic tanks are prone to breaking off. and causing other problems.
Title: Re: Blues Jr. Reverb Problem
Post by: sluckey on September 24, 2017, 10:42:54 am
Probably not much if any differences. The Accutronics unit does not include rubber grommets.
Title: Re: Blues Jr. Reverb Problem
Post by: dpm309 on September 24, 2017, 01:31:00 pm
Thanks Sluckey. I will go with the Belton unit. From the reviews I read, the MOD tank sounds different than the typical Fender reverb, more of a Marshall type sound.