Coytee Posted September 13, 2006 Share Posted September 13, 2006 http://search.ebay.com/search/search.dll?from=R40&satitle=isotap I don't know how good the pricing is. I've got a $10 bid on one right now. With all of these flooding the market maybe my bid will stick. none the less, even at $25, if they help isolate from hum as I understand it, perhaps even that is a great price?? * not affiliated with seller(s) and all that yuk. Quote Link to comment Share on other sites More sharing options...
Guest " " Posted September 13, 2006 Share Posted September 13, 2006 If you want to eliminate hum, check out this link. This is the approach used in $1500 - $3000 line conditioners. http://home.comcast.net/~thomasw_2/CheapskateBP1.html Quote Link to comment Share on other sites More sharing options...
Duke Spinner Posted September 13, 2006 Share Posted September 13, 2006 bear in mind, thier only 275 va ...... Quote Link to comment Share on other sites More sharing options...
Guest " " Posted September 13, 2006 Share Posted September 13, 2006 Duke Spinner yeah, I know, the isotaps are not high current devices. using transformers available from partsexpress, and the link i provided below, you can get to 1000va with one transformer , and 2000va with two, if you have access to a 220 line. Quote Link to comment Share on other sites More sharing options...
Coytee Posted September 13, 2006 Author Share Posted September 13, 2006 Ok, gimme a quick lesson here then... I don't know what all that va stuff means. Are you basically saying they won't work for all my stuff.? Here's why I ask... I spoke with the company selling "mine" (that I just won on ebay for $10) and they said they had several. They told me they'd honor the price on ebay for others if I wanted to get several. (I was thinking 3, one for stereo amp, one each, for MC-30's) Are these up to that task? If not, no sense in buying 2 more than need be if they're underpowered. And Fritzie... where DO you find some of these gems you find!!! you da man! Ok guys...hurry & tell me... Yes / no... do I want to buy THREE of those at $10 or leave it at the single unit and build/make the heavy one Fritz showed us? Quote Link to comment Share on other sites More sharing options...
Guest " " Posted September 13, 2006 Share Posted September 13, 2006 Here is a good link to some info about Isolation transformers. http://www.blackmagic.com/ses/bruceg/EMC/isolatrans.html Getting back to the balanced power supply, Did you step thru the three pages about constructing the balanced power supply? There is a next tab at the lower right of each screen. In terms of a recomendation, at the price your indicating for the isolation transformers, you can certianly buy them, experiment, and sell off at some later point in time, if you go the balanced power supply route later. The construction of the balanced power supply, while not a complex project, requires some attnetion to detail, logistics, and procurement for the parts. The isolation transformers are useful under some senerios, your call if the snerios are applicable to your location. Quote Link to comment Share on other sites More sharing options...
Duke Spinner Posted September 13, 2006 Share Posted September 13, 2006 ya wanna build that one ... the one ya bought is only good for a few devices, combined at once i.e. ...preamp / CD player Quote Link to comment Share on other sites More sharing options...
DRBILL Posted September 13, 2006 Share Posted September 13, 2006 I run three. One for MARK III, CD, FM; One for MARK III, TT, Rell-Reel. One for Williamson. They are plugged into a FURMAN RP-8. Be sure to get the kind that have the three prong plug for grounding. $10? Go for it. Shipping will kill you, thouigh. DRBILL Quote Link to comment Share on other sites More sharing options...
Guest " " Posted September 13, 2006 Share Posted September 13, 2006 Here is a DIY balanced power supply that uses 2 transformers for 1600 VA's. http://home.comcast.net/~thomasw_2/CheapskateBP4.html Quote Link to comment Share on other sites More sharing options...
Coytee Posted September 13, 2006 Author Share Posted September 13, 2006 In the real world, what does a VA mean and what is a 1600 VA item going to do for me, that a 400 VA item won't? Also, let me rephrase a question... Would a 400 Va item carry a SINGLE tube amp? If so, fine. If not, what MIGHT happen if said tube amp is connected to it? Any prospects of damage? (tube amp defined as McIntosh MC-30's and/or MC-2102) Would a solid state amp be any easier? harder?? I went ahead and nabbed 3 of them. Heck... $30 (total) for the three plus about $25 on shipping (he's calling me back to confirm) So, for under $100, *if it works*, I can help reduce some hum out of these klunky, inefficient pile drivers? [6] Heck... I sometimes wonder if I can hear hum that existed in the recording studio coming out of these things... [] Quote Link to comment Share on other sites More sharing options...
Guest " " Posted September 13, 2006 Share Posted September 13, 2006 No it will not work on a MC-2102 if it is only rated at 400 VA. The MC-2102, when plugged into a 120 volt outlet, draws 600 VA's (VA=E*I) at max power. Using an isolation transformer above it's rated output will cause quite a bit of hum due to the saturation of the core, as well as generating quite a bit of heat, things will smell bad, followed by silence...the transformer will burn out (unless it has a circut breaker or fuse). MC2102om.pdf Quote Link to comment Share on other sites More sharing options...
Coytee Posted September 13, 2006 Author Share Posted September 13, 2006 No it will not work on a MC-2102 if it is only rated at 400 VA. The MC-2102, when plugged into a 120 volt outlet, draws 600 VA's (VA=E*I) at max power. . Ok...Ok... I'm not being argumentative here (just so you know), but rather showing my ignorance and trying to clarify inside my peabrain. You referenced at 'max power' above... may I infer that if it's (2102) crusing along at say 10 watts peak, then it might work? Do you really thing if I have this thing mated to the HF section of these monsters, I'm going to be using it at max power? I may be a dumb (loud volume) listener but I hope I'm not that dumb. [] Now if it were on the LF section, you might have a point. As it is, the highest I've seen the needles is 'probably' 10 watts, so let's even bump it to say 30 (ouch). If the 2102 is bad news for it, how about the 30's? I guess the dbx amps will suffocate it too (the BX3 is something like 100x4 wpc) Ok, so I can use it for my outboard items, cd/dvd/Peach? Perhaps MC-30's? Quote Link to comment Share on other sites More sharing options...
Guest " " Posted September 13, 2006 Share Posted September 13, 2006 all you need to do is determine the power your equipment draws at rest, but turned on. Maybe some other forum members can chim in if they have power devices with current indicators. Typically an amp has a respectable current draw even at idle. If the amp ildes at 33% power consumption you start out at 200 VA's at idle, assumping the headroom remaining on the 400VA isolation transformer is 200VA's, typically you can estimate the deliverable remaining power to your speakears as the square of your consumption which would be about 25 watts per channel on the remaining 200 VA's. If someone with an MC2102 can provide your idle current draw, you would have better numbers to go with. If your idle draw is 300VA's, your looking at only being able to crank out 12 watts per channel before saturation. Doesn't look good in my view considering the initial draw from a cold start would saturate the transformer, before you get to the ilde stage. The DX4 amps, we would need the current draw to answer your question. Quote Link to comment Share on other sites More sharing options...
Kriton Posted September 13, 2006 Share Posted September 13, 2006 OKOK, now I am really confused - so label me the village idiot - let me give you a hypothetical: Say I have an isolation transformer that is rated at 500 watts continuous, and I have an amplifier that has rated consumption of 40 watts rest, 580 watts at normal use, and 1800 watts max before clipping - I am going to assume that plugging this thing into THAT transformer is big mistake? I mean, how many watts can be consumed by an amp which is powering a pair of klipsch speakers with 98dbs for 1 watt? There is little way I am going to run those things hotter than that, so do I have to worry about the consumption being that marked? If the amplifier does go beyond the 500 watts, the circuit breaker in the isolation transformer trips - will that hurt any of the components???? While amps are dynamic, what about pre-amps? And how is the wall outlet able to deal with these huge spikes in wattage? I am trying to get a handle on these things too, and I really liked the DYI pages on the balanced power supply, read the papers, and I understand in theory, but ... Thanks - K Quote Link to comment Share on other sites More sharing options...
Guest " " Posted September 13, 2006 Share Posted September 13, 2006 first of all, here is a link that helps get part of the info that will answer your question. The remaining piece is the formula for determining VA or voltage amps (VA=E*I), since most transformers , UPS, line conditioners are rated in VA's. http://www.angelfire.com/pa/baconbacon/page2.html your question "Say I have an isolation transformer that is rated at 500 watts continuous, and I have an amplifier that has rated consumption of 40 watts rest, 580 watts at normal use, and 1800 watts max before clipping - I am going to assume that plugging this thing into THAT transformer is big mistake?" Answer. The transformer has a voltage amp rating of 480 VA's. The current involved here is 4.16 amps. The amplifier indicated (the rest value is more of one for a tuner, CD player, etc, but I'll use it for math purposes) rest value of 40 watts means that it draws .33 amps at rest, and less than one voltage amp. point of comparisson, I just checked my main amp. If the amp is turned on, doing nothing, it draws 2.57 amps, or 308 VA's. My amp is a 160 watt per channel class AB amp. The indicated normal usage of 580 watts is 576 VA, current involved is 4.8 amps. At this point you have exceeded the ability of the transformer, and now you can expect hum being inroduced due to saturation of the core, as well as heat being generated, voltage is also falling (isolation transformers can provide voltage with in 3% if not saturated), your dynamic range just when down the toilet. Now the value you provided of 1800 watts (this would be in the area of a 350 watt per channel stereo amp), means that it draws 15 amps of current, or 1800 VA's. Unfortunately, this will not happen, since the transformer will limit the amp to 4.16 amps of current, or 480 VA's, basiclly, using your numbers, the amp will be limited to 1/4th it's rated power. You would probally shut this amp off as it passed 480 VA's, unless you like lots of distortion, and the sound of a humming transformer in the back ground, that was sizzling hot, and smelling like road asphalt. Until the transformer craps out (unless it has a breaker or fuse, then it would be re-set city). As far as your question about how much power does it take to produce the 1 watt your k-horns need. Look at my amp, it's using 308 VA's just be being turned on, no music playing. The ISOTAP on ebay is reprotedly rated at 400VA's. So now I play a song. At minus 15 db, I am already at 6.07 amps or 720 VA's ( I need to get to +- 0 db to be at 1 watt). Of course the values will vary based on your amp, the design (class A, class AB, etc). But as you can see, this is not as intuitve as it would seem on the surface. I hope this info is helpful. I recall during the early 70's using isolation transformers that were under sized for what i was trying to us it one, the humming and buzzing associated with core saturation is unforgetable. It would really be helpful if someone with one of these high end tube amps chimmed in with the current draw at idle (on but not playing music). I am kinda thinking a tube amp might draw more at idle than an SS amp would. Quote Link to comment Share on other sites More sharing options...
Coytee Posted September 13, 2006 Author Share Posted September 13, 2006 Ok, so all that jibber jabber boils down to I just bought three boat anchors? [] [] [] [] (as far as using them for my amps) when they arrive & I toss them into the closet, I'm going to tell my wife I won them in a drawing or something... [:$] Quote Link to comment Share on other sites More sharing options...
Kriton Posted September 13, 2006 Share Posted September 13, 2006 Fritz, Wow - cool, I think I understand. Those amp numbers by the by are for my Sunfire 400/7 amp, directly from their owner's manual - but this is a strange animal, so I used it for the hypothetical... The sensitivy of the RF-7's that I am running is 102dB @ 2.83 volts/1 meter, which is all the more confusing. I can not see even coming close to mustering a watt as the volume would be incredible. I need to get the calculations down... Thanks for taking the time to explain it... K Quote Link to comment Share on other sites More sharing options...
Guest " " Posted September 13, 2006 Share Posted September 13, 2006 Coytee Might be worth the effort to start a new thread asking if anyone knows the current draw at ilde on your amps. If a forum member has one hooked up to a line conditioner with a current usage indicator they can give you that answer. Also may be useful to pool folks that are using these ISOtap devices and get some data as to the type of amps they are using them with. one forum member is indicating they have mono blocks connected to individual isotaps. I think the tube amp in question is 40 watts per mono block. So that math seems to work out. Quote Link to comment Share on other sites More sharing options...
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