Members NaturalBornBoy Posted January 19, 2012 Members Share Posted January 19, 2012 The one in the OP looks something like what Bob at Eurotubes uses. http://www.eurotubes.com/euro-Marshall-DSLTSLV.htm Link to comment Share on other sites More sharing options...
Members Y0UNGBL00D Posted January 19, 2012 Members Share Posted January 19, 2012 i use the weber one. the bias rite. and a multimeter. one bias trim pot, two EL34s. which id have been smarter and gotten the right angle ones though Link to comment Share on other sites More sharing options...
Members Jack Tone Posted January 19, 2012 Members Share Posted January 19, 2012 i use the weber one. the bias rite. and a multimeter. one bias trim pot, two EL34s. which id have been smarter and gotten the right angle ones though I never heard of those. Just looked them up. I've got the Weber also, and the right angles are just an adapter you plug your bias rite into. Great idea! And to Wyatt and NaturalBornBoy...One of my amps is a Line 6 Spider Valve head. It's got 4 trimpots, one for each tube Link to comment Share on other sites More sharing options...
Members NaturalBornBoy Posted January 19, 2012 Members Share Posted January 19, 2012 And to Wyatt and NaturalBornBoy...One of my amps is a Line 6 Spider Valve head. It's got 4 trimpots, one for each tube In that instance, I can see the need for 4 probes but in my case where I have 2 trimpots, one for each pair, is it right to say that I only need 2 probes? One for each outermost tube? Link to comment Share on other sites More sharing options...
Members Jack Tone Posted January 19, 2012 Members Share Posted January 19, 2012 In that instance, I can see the need for 4 probes but in my case where I have 2 trimpots, one for each pair, is it right to say that I only need 2 probes? One for each outermost tube? Yes, especially if you know the tubes are matched pretty well. I only have two probes on my weber. It just takes a little longer with that example. Link to comment Share on other sites More sharing options...
Members Spizzledude Posted January 19, 2012 Members Share Posted January 19, 2012 In the words of my dad "I'll probe your bias!!!!" Link to comment Share on other sites More sharing options...
Members Jack Tone Posted January 19, 2012 Members Share Posted January 19, 2012 Hi Zentman welcome back! Link to comment Share on other sites More sharing options...
Members Crunchtime Posted January 19, 2012 Author Members Share Posted January 19, 2012 OP, here is a bias rite for sale on ebay. http://www.ebay.com/itm/Bias-Rite-BR-4-Digital-Tube-Amp-Cathode-Current-Meter-/400270913949?pt=LH_DefaultDomain_0&hash=item5d3201719d#ht_619wt_1398 Thanks Laura, I ordered the Bias Rite. If it's good enough for ValveQueen, it's good enough for me. Link to comment Share on other sites More sharing options...
Members Megadeth Man Posted January 19, 2012 Members Share Posted January 19, 2012 The one in the OP looks something like what Bob at Eurotubes uses.http://www.eurotubes.com/euro-Marshall-DSLTSLV.htm Yeah, that's the Alessandro unit. It measures plate current directly. Link to comment Share on other sites More sharing options...
Members Y0UNGBL00D Posted January 19, 2012 Members Share Posted January 19, 2012 I never heard of those. Just looked them up. I've got the Weber also, and the right angles are just an adapter you plug your bias rite into. Great idea! And to Wyatt and NaturalBornBoy...One of my amps is a Line 6 Spider Valve head. It's got 4 trimpots, one for each tube yeah they sell them modularly, as in, you can buy the whole getup, or jsut the probe if you already have a multimeter, etc. i have to remove my chassis when i bias becaus ei didnt get teh 90 degree probes because i am a raging moron. Link to comment Share on other sites More sharing options...
Members NaturalBornBoy Posted January 19, 2012 Members Share Posted January 19, 2012 Yeah, that's the Alessandro unit. It measures plate current directly. Pretty pricey stuff http://www.ebay.com/itm/Alessandro-Bias-and-Matching-Meter-/230320359614?pt=LH_DefaultDomain_0&hash=item35a029c8be#ht_1455wt_1398 What's the advantage of using the Alessandro as opposed to using a digital multi-meter to bias my DSL? Link to comment Share on other sites More sharing options...
Members guitarbilly74 Posted January 19, 2012 Members Share Posted January 19, 2012 You don't need a probe at all with the DSL. A regular multimeter will do. You will be measuring mV not mA, so set your multi-meter correctly. The ideal setting for the 100w is between 80 and 90, but I think 90 is too hot for my taste. Connect the black wire of your multimeter on the middle prong and use the red wire to test the left and right prongs. You will notice that as one side goes up, the other goes down, so you have to adjust each side until both sides are balanced. That's all there is to it. Super easy. Link to comment Share on other sites More sharing options...
Members NaturalBornBoy Posted January 19, 2012 Members Share Posted January 19, 2012 You don't need a probe at all with the DSL. A regular multimeter will do. You will be measuring mV not mA, so set your multi-meter correctly. The ideal setting for the 100w is between 80 and 90, but I think 90 is too hot for my taste. Connect the black wire of your multimeter on the middle prong and use the red wire to test the left and right prongs. You will notice that as one side goes up, the other goes down, so you have to adjust each side until both sides are balanced. That's all there is to it. Super easy. Thanks Billy I guess with something like the Alessandro unit, you can see the bias values of both sides at the same time, as opposed to having to switch the red wire from one prong to the other. Link to comment Share on other sites More sharing options...
Members guitarbilly74 Posted January 19, 2012 Members Share Posted January 19, 2012 Thanks Billy I guess with something like the Alessandro unit, you can see the bias values of both sides at the same time, as opposed to having to switch the red wire from one prong to the other. Sure. but who the hell wants to pay almost 200 {censored}ing dollars just so they don't have to switch a little wire from a side to the other? You don't need that {censored} bro. $15 multimeter from Radio Shack. That's all you need. Link to comment Share on other sites More sharing options...
Members NaturalBornBoy Posted January 19, 2012 Members Share Posted January 19, 2012 Sure. but who the hell wants to pay almost 200 {censored}ing dollars just so they don't have to switch a little wire from a side to the other? You don't need that {censored} bro. $15 multimeter from Radio Shack. That's all you need. I know bro It's not like I have 200 to spare anyway Gonna pick up a multi-meter next week. Do they all come with alligator clips or is that an add-on accessory? Link to comment Share on other sites More sharing options...
Members guitarbilly74 Posted January 19, 2012 Members Share Posted January 19, 2012 I know bro It's not like I have 200 to spare anyway Gonna pick up a multi-meter next week. Do they all come with alligator clips or is that an add-on accessory? It's an add-on for like $2 for a pack of 10 Link to comment Share on other sites More sharing options...
Members NaturalBornBoy Posted January 19, 2012 Members Share Posted January 19, 2012 It's an add-on for like $2 for a pack of 10 Well {censored} me Even I have 2 bucks Link to comment Share on other sites More sharing options...
Members Megadeth Man Posted January 19, 2012 Members Share Posted January 19, 2012 Pretty pricey stuff http://www.ebay.com/itm/Alessandro-Bias-and-Matching-Meter-/230320359614?pt=LH_DefaultDomain_0&hash=item35a029c8be#ht_1455wt_1398 What's the advantage of using the Alessandro as opposed to using a digital multi-meter to bias my DSL? You don't actually need anything to set the bias beyond your eyes, ears and a screwdriver to adjust the trimpot. The reasons why you adjust the bias are: so the valves don't red plate, so the amp sounds/reacts how you like it and to increase the longevity of the valves by not running them hotter than necessary -- this last one is optional. So, in an amp with one bias trimpot you can start it off on its coldest setting and gradually bring it up until the amp sounds how you like it. As long as the valves aren't red plating then job done. If the amp has more than one bias trimpot then you probably want to start taking measurements as it's simper to tell how close the valves are to being balanced than without one. The main reason for having an analogue unit that measures plate current directly, like the Alessandro, is to balance and match the valves accurately. This is done by adjusting the bias trimpots, the balance trimpot (if the amp has one) and physically swapping around or replacing the valves for a better match. The reasons to do this are to get the best possible sound, reduce/eliminate hum and, in the worst case scenario, to avoid nuking the output transfromer. Valves may be balanced at idle but when you start playing they can turn out to be badly matched. The milliameters will clearly show this. What you want to do when biasing the DSL with a multimeter is to ensure both sides are as equal as possible. And instead of just blindly biasing to some random figure use your ears to bias it as cold as you can with the amp still sounding good. That will ensure you're not needlesly burning off valve life. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.