High Speed Wrap Up Of An Onkyo A-7090 Integrated Stereo Amplifier.

Wrapping up some servicing of an Onkyo A-7090 Amp, have a good and safe weekend !

B&K AV5000 Series 2 Evaluation Part One

In this part one video I perform an initial evaluation of a B&K AV5000 series II multi-channel power amp, which was brought in by a customer who stated there may be an issue with an input level pot that may be causing some signal loss / noise. During the initial inspection I observed a connection issue at the power switch as well as potential connection issues elsewhere that should be looked into further.

Sometimes You just gotta Dig, Can You Dig it?

So, You need them potentiometers (pots.) and switches thoroughly cleaned and re-lubricated? Of course ya do ! Let's face it, with vintage audio equipment it is extremely common to experience all sorts or noise / scratchiness, diminished signal / loss of signal etc. associated with "crusty controls". Yes, over the span of decades dirt and other such debris plague controls and cause them to misbehave. Additionally, factory lubricants within a variety of pots also become degraded as well. Obviously, for the techs that may be reading this brief article, we know such signal issues can also stem from other areas. However, even if that is the case, thorough servicing of controls is a wise course of action in multi-decade old equipment (continued below).

For You prospective customers that are a bit more "audio gear savvy", as well as You "audiophile" class of humanoids, this may be of interest as well. Regardless, for those that prefer not to perform the above maintenance on their own equipment, this may help provide some clarification as to what is commonly encountered during the maintenance of such controls. Rather than a lengthy description of proper cleaning and lubrication technique, of which believe it or not, would require a whole separate article, I believe a few words on accessibility is more important to mention, along with a few photo examples :-)

Yes indeed, sometimes there is a lot of digging involved to access various pots and switches and other times it's a breeze ! In the case of the Onkyo amplifier in the accompanying images, the removal of several staggered boards and the manipulation of wiring etc., is necessary to gain access to the topside of the pots. However, the openings to introduce cleaner and lubricant are located on the bottom side of the pots. That being the case, they are all mounted to the board on the very bottom of the chassis and will need to be de-soldered and of course removed along with the inner face panel that remains. So, the moral of the story is, sometimes despite the method / process used to service controls, it's often getting to them that poses the real challenge and dictates the cost of such service.

So again, this was just a brief "digestible" article bringing the above mentioned into the spotlight for the purpose of showing what can be encountered within numerous makes and models of equipment. Unfortunately, it's not always as straight forward as grabbing the favorite contact cleaner and jumping in with ease. Till next time...Peace, Love Rock n Roll and of course Vintage Audio !