Marc Rising Star's
Tech Answers -
Answers for Questions relating to VINTAGE AUDIO EQUIPMENT
© 2001-2014 Ultraelectronicactive.com*
Star's Vintage Audio Equipment currently FOR SALE
Tube Guitar Amplifier
value - restoration - how to sell
Question: I have a small kalina tube amp made by valco company. Looking for value and any information
Answer: The Valcos I have seen generally went for in the $150 to $350 range and in rare cases up to $475. Where all original (original speaker, original knobs, original handle and so far) seems to up the value. But then again, you might want to check eBay completed auctions to get a clearer picture - ideally with amps that match yours as close as possible.
The tendency for value in general is that value increases more and more with time, so in a few years it may be worth even more - and that pattern has been developing consistently. Unfortunately Guitar amps is not my main line and I have not been following price developments very closely.
Question: kalina tube amp - Best place to sell if it is worth anything
Answer: eBay (if wanting to make the needed time and money investment), or lists where tube guitar amps are sold, such as rec.musicmakers.com, harmony central, sonic-state, etc. If you know exactly how much it is worth you can try craigslist as well, as free and easy to do, but be well prepared for hard core bargainers who tell you the amp is "worth nothing" and show you reasons trying to proove, that you have a piece of junk on your hands form which they are rescuing you; And then those who wanting to trade their car stereo, iPod, or TV for it. And: lots of calls where no-one ever shows up after telling you repeatedly they "definitely" are going to be there.
Question: kalina vintage tube amp - I was told not to plug it in
Answer: Correct for any vintage tube gear. Ideally one would test first and if all is okay: power up by applying power very slowly with a variable AC transformer (Variac) - Ideally while closely monitoring how much current the amp draws. This helps to revive and restore capacitors which otherwise, if just plugging it in, would get jolted and these become leaky - meaning leaking current.
I usually replace all capacitors throughout the unit, where the most important are: All of the the capacitors in the power supply, and the signal coupling capacitors between the driver and the output tube(s) - but again ideally replace ALL capacitors as these are likely all of the same age. Resistors drift in value too, but that usually is not an issue. contact cleaner on tube sockets, switches and potentiometers.
Even if power is brought up slowly and the amp is working I do not recommend using it without replacing capacitors. Likely what you will notice is that it will work first and then get weaker with more and more hum and distortion - bad capacitors. If left un-attended this can bring down the output transformer and/or the power transformer (relatively expensive parts), as "leaking" capacitors will over load the tubes and power supply.
One important piece of advice that if ignored, can make repairs expensive: never ever use the amp with a different type of fuse than what is supposed to be there - the fuse is to protect the circuit (and your life!), and if ignored expensive parts will get damaged.
Question: kalina vintage tube amp - I am interested in knowing what would be involved restoring it myself
Answer: Not rocket science, but educate yourself about the dangers involved: High voltage - how to handle and how to avoid exposure by (at least): never working on it when it is plugged in, properly dis-charging capacitors before working on the circuit, using an isolation transformer. What parts can cause to electrocute the guitar player if defective, and etc. And I recommend to do a lot of home work in research on the web before starting to get into it. Skills needed for restoration: a lot of soldering - need to know how to make nice flowing connections - practice with copper wire first until you feel confident.
Take photos before you tear apart, so that you can see how it was before you started working. Mark wires and other parts before removing them so that you know where they need to go back to, draw what you see on a piece of paper, and so on.
Schematics for these amps can usually be found on the web to be downloadable for free. If they still exist, try: schematicsheaven.com
If was to restore the amp to reliably working condition to perform as close as possible to original specs (to become a stage-reliable instrument for a professionally working musician): likely in the $250-$350 range. Working on tube geear takes a lot of time - be prepared, if you do it yourself.
Guitar Gear For Sale
More Tech Answers
| Buy Top All Audio Equpment