Yorkville Sound: Bass Amps FAQ

Q: I am having trouble finding an amp that works well with my 5-string bass. Do you have any suggestions?
A: Most of the new 5 and 6-string active basses coming on the market are instruments with much higher gain structures and lower frequency response capability than in previous generations - generally far greater than any amplifier manufacturers ever expected to have to deal with. Some instruments take this to even greater extremes. Consequently there is often a need to try various combinations of power and speaker selection to reach the results needed to suit individual playing styles and musical genres.
Interestingly, our company is well populated with Bass players starting with our President, the Vice President of sales and Marketing and a number of others throughout the organization. They all have a personal interest in Bass Amplification, and Yorkville has been in the business of designing and building this type of equipment for many years. As a result, the BM400 has tons of headroom (apx.700 Watts full-wave peak) and the head version is great for 5- or 6-string bass in combination with perhaps a Pulse PS18 subwoofer and a BC210 bass cab for the normal bass range. Try it out. The sub has a low-pass filter so you won't need a crossover.

Q: I have had the great fortune to come across an old Traynor amplifier called a 'Group One B'. What a great little amp! I would like some specs on it, but it's not in your Traynor archive on your web site. Here's some info about it... Serial No.: 5011012. Controls: Hi & Lo inputs, Volume, Bass, Treble, 3-position Lo-Mid-Hi frequency selector switch with a 'Fine Tune' (freqsweep) knob and a cut/boost knob that affect the range selected with the 3-pos. switch. There's also a Master Volume. On the back of the unit there is a 115V, 3A accessory socket, two speaker outputs at 4 ohms & 50W each, a circuit breaker, a pre-amp output jack, and a power amp input jack. The chassis is exactly the same as the Mono Block B, and it is a solid state amp as well. Having said all that, here are my questions:

When was it manufactured?
How rare is it? Do you know a current value? Original market value?
Was it designed as a bass amp? It sure sounds great with guitar...almost impossible to tell that it's solid state!!! Wow!!!
How do you get inside the damn thing? I want to clean it up a bit, but I can't get under the hood. - How embarrassing.
A:

Jan./75
It listed for around $300.00 in Canada back then. Sorry, we don't know the current value. Try a web site called Velvet Black http://www.informatik.uni-bremen.de/~dace/vb/models.html. They might have it listed.
It was designated a bass amp but like most Traynor bass amps back then worked well for guitar.
Use a screwdriver or two, one on each side, to get under the plastic fasteners on the top plate and pry them up. You should be able to re-seat them afterwards with a plastic mallet but if they get damaged you may have to drill out some of the plastic anchors and use self-tapping screws. (Neat series of amps but the fasteners were a little far-out).

Q: I've been researching speakers and cabinets a bit and although I'm no electrician, I know enough to make a good purchase. I own a Gallien-Krueger 800RB head which pumps 300watts into 4ohms or can biamp 200watts @ 4ohms and 100 watts @ 8ohms. My original plan was to purchase an SWR Goliath III Junior (210") and a Big Ben (18"). The price of these cabinets together would be near $2000, which is a bit much. A Yorkville 2x10" and a 15" would be $950, including GST, if the prices on your web site are still current. What really got my goat was the fact that SWR makes a lot of their cabinets with Eminence speakers. Now I may be missing something but isn't that the same as your company uses? That's some price difference!
To my surprise my music teacher (guitar player) actually owns some Yorkville cabinets, which he says sound great and have been very reliable. He is a professional performer and recording musician so I trust his opinion. I am eager to give them a one-on-one trial against the big names.
Now to the point of my e-mail. I was on the eminence web site and was looking at their products and their various speakers. I was wondering if you guys make or could special order an 18" cabinet. I think that it would be an excellent addition to your line of products and an affordable 18" would sell well. 18's are not very popular among younger guys because not many people make them and they are not widely available. If not the 15" will probably be fine, but 5-strings do sound incredible with the big sub-woofer!
A: We produce a few different single-eighteen cabs. They're all for PA but should work fine for bass guitar as long as there's another cab to produce mids & highs. The Pulse PS18 even comes in the same color and covering as our bass cabs. It's listed on our site. Sadly there's nothing with an eighteen that is specifically for an 800RB - that's G-K's job, I guess - but if your dealer has a PS18 to rent, give it a try along with a BC210 for mid-highs. Set the 800RB's crossover down around 100Hz.

Q: Solving radio frequency interference in a bass (guitar) amp.
(This time there's no question. The customer came up with a solution. His problem was radio frequency pickup in his bass amp.)
A: I connected 2 47pf capacitors from the hot on my volume control to the ground of my output jack. This has solved my RF interference but also lessened the hum associated with fluorescent lights. I thought this might be of help to you. This did not alter the tone on my bass even with the treble cranked up.

Q: I have a Traynor 150 bass amp with 2x15 speakers. As far as I can tell the amp and cabinet are 30+ yrs old. I am wondering if it is a collectible. It still works excellent and sounds great even though the speakers are in rough shape.
A: It's really hard for us to say what is or isn't a "collectible". As a manufacturer all we know is the value of things we build and sell now. I guess it's a bit like asking Ford what a '65 Mustang's worth, they probably wouldn't know either. However there are websites which specialize in such things. There's one called Velvet Black. It's . It's all about old Traynor stuff. Check it out.

Q: How do you remove the chassis from the cabinet in an old Traynor YBA-2B Bass Mate amp?
A: It depends on the vintage. In old amps you undo the 4 top screws which lets the chassis drop down, then you pull it out the back. In the later versions, you undo the 4 top screws and loosen the 4 side screws then knock the lid loose and lift it off. This gives you access to the inside of the chassis. If you have to remove it, remove the side screws. You should find the schematic diagram on the underside of the lid.

Q: I have recently built a bass cabinet that I plan to Bi-amp. The 15-inch is a 4 ohm speaker. The 2 ten inch speakers {for punch} are also 4 ohms ea. I know that depending on the wiring I can wire the 10 inch speakers @ either 8 or 2 ohms. I prefer to run them @ 4 ohms because I think my second amp will run better @ 4 ohms. How do I go about creating a dummy 8 ohm load so that the 15" will run @ 4 and the two 10`s will run @ 4ohms?
A: The problem with using resistors in a situation like this is (a) you'll have to use either a big honkin' resistor, based on whatever the power of the amp is, or a whole bunch of smaller ones. (b) The resistance is just going to sit there soaking up power and robbing you of efficiency hence sound.
I think you might want to consider some other solution. If I were you I'd put the 10's in series for 8R and run the 15 @ 4R, then just balance them out with the volume controls on the power amp(s). If you're determined to use resistors however, you would put the 10s in series for 8R then put a (BIG) 8R resistor in parallel with them (across the input jack maybe?). But really, I wouldn't recommend it.