Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: pbman1953 on August 04, 2015, 07:03:58 am

Title: Traynor YBA-3 Custom Speaker config question
Post by: pbman1953 on August 04, 2015, 07:03:58 am

After doing my latest mode I noticed on my schematic a 8 inside a triangle next to the speaker jack drawing.


Does this mean the amp is rated at 8 ohm?


The speaker jacks are wired in series, an option I don't like. Has any other owner re-wired to be parallel?  Traynor had 8 ohm and 16 ohm cabs for this amp. I tried 16 ohm and it does not sound good. It sounds the best at 4 or 2.Most of my cabs are 4 or 8 and I've read that this amp can handle 2 ohm.


 I just want to be safe


 
Please let me know your opinions


Thanks

Title: Re: Traynor YBA-3 Custom Speaker config question
Post by: sluckey on August 04, 2015, 08:00:33 am

There are several different schematics of this amp. Some show a multi-tap OT secondary with a 2Ω/4Ω switch and parallel jacks, some show a 8Ω output. The 8Ω output schematics have that "triangle 8" notation and the speaker jacks are wired such that if you plug into the EXT jack you will disconnect the SPKR jack. I would respect the output impedance on a quad of EL34s. Using a 4Ω cab on the 8Ω jack 'may' be safe, but using a 2Ω cab on the 8Ω jack would be inviting expensive trouble.

I don't own this amp but you can certainly rewire the speaker jacks if you wish. Note that the EXT jack is isolated from chassis.

Title: Re: Traynor YBA-3 Custom Speaker config question
Post by: pbman1953 on August 04, 2015, 08:23:56 am

You're right on the many schematics. Shown below is the link for mine-






http://www.freeinfosociety.com/electronics/schematics/audio/traynor_customspecial_yba3c.pdf (http://www.freeinfosociety.com/electronics/schematics/audio/traynor_customspecial_yba3c.pdf)

Title: Re: Traynor YBA-3 Custom Speaker config question
Post by: jjasilli on August 04, 2015, 08:41:04 am

The OT secondary has "8Ω" stated next to it.  There are several numbered triangles in the schematic which seem be test points; see the box in the lower right corner of the schematic.

Title: Re: Traynor YBA-3 Custom Speaker config question
Post by: pbman1953 on August 04, 2015, 08:48:23 am

Ahh, saw that. So I suppose not to go lower than 4 ohm


In that case , it stays as is.


My configs would be-


1- 8 ohm


1- 4 ohm


2- 8's- daisy chained to be 4 ohm


2- 4's - using both jacks to be 8 ohm


I'm covered


Thanks