I shouldn't have said "transformer." I don't know what the conversion circuit is. The point is, the powered subwoofers with speaker-level inputs would have circuits very similar to the passive units available in car audio. There's no reason to turn your nose up at components common to car audio; they deal with complex wiring, high power, and high current. Many carry very high-res signals between components by Focal, Alpine, Blaupunkt, Boston Acoustics, upscale Pioneer, Kenwood, and of course JL Audio.
Besides, it'll only cost about $15-30 to find out if one of these automotive units will do the trick, and just about everything these days has a 30-day return period. |
Johnny, as I indicated in my initial post in this thread I'd be skeptical that a cheap transformer oriented towards car audio, and perhaps even Carver's Z1 Coupler, would do justice to the OP's system, and to a JL sub in particular. As I'm sure you realize, all transformers are not created equal, and that is probably especially true in the deep bass region.
Also, are you sure that "any powered subwoofer that has speaker inputs has a similar transformer inside to pass the signal to the internal sub amp"? I have no particular knowledge of how that is generally done, but I would expect that in many or most cases it is done with resistors configured into a voltage divider circuit, not with transformers, resistors being a much less expensive approach compared to a quality transformer.
Regards,
-- Al |
Kal Rubinson (Kr4) is right. There is a simple answer; transformers abound in the auto sound world for converting speaker output signal back to preamp level signals. There used to be some available for home audio. Carver made one in the '80s to enable receiver owners to use his amps. These days they're mostly in car audio. But if you match power capacities you should be fine. It's a passive device, and any powered subwoofer that has speaker inputs has a similar transformer inside to pass the signal to the internal sub amp. You'd be supplying this link between your Jolida and your JL. It's safe and it's not rocket science. And it's really inexpensive. |
Oldrider,
Thor is in Texas now close to Dallas. Ted is one of the good guys in audio. If you want I can ask him if they work on Jolida products or you can look him up. |
If you want to keep the Jolida with the JL sub, I think you'll have to have the Jolida modded to add a stereo pair of line level outputs. If I were you I wouldn't get frustrated at JL--or even Jolida. As Kal said, each vendor makes its decision of features based on market demand and to make the unit more affordable. Putting speaker level inputs on subs adds cost that few people will use. The same goes for lower-priced integrated amps. I used to use an Onkyo A-9555 integrated amp. It's a nice-sounding unit, but has no preamp outputs, and if you use the headphone jack, it automatically turns off the speaker outputs. Otherwise I could have used a stereo phone plug to RCA stereo adapter cable to use a sub. But it wouldn't do that and I moved on. Now I use separates and my last two line stages have had two pairs of line level outputs. But there are plenty of integrated amps at every price level that have a pair of line level outputs. Audio Advisor has a Vincent Integrated for $399 (marked down from $900) that not only has preamp outputs, it has a USB port and a built-in DAC. So does the NAD 326BEE at $549 and many others. Also, the current production Jolida JD302BRC or CRC integrated amp also has preamp outputs. |
...Just don't want to purchase another amp/preamp at this time. Just took deliver of a new Marantz Super Audio SACD player, along with having one of their nice TT15 tables on the way from Crutchfield..... Ironically, a really good match for the SACD player and turntable you just bought is Marantz's matching PM8004 Integrated Amp. It is an amazing amp at the price and I heard a demo of the SA8004 playing a Redbook CD through it to a pair of $10K Sonus Faber Cremona M speakers. This CD player pulled out detail and ambience I didn't know existed on recordings I'm very familiar with. And the amp brought out the best in the ten-times-as-expensive speakers, with an organic, transparent midrange, neutral tonal balance, and amazing control over the bass of a pair of ported dual-woofer towers. The TAS review is very enthusiastic and mentions that the built-in MM-level phono preamp is excellent. And yes, it has a pair of preamp outputs. To keep signal transfer high and expenses down when connecting to the JL Fathom, you could get a pair of AudioQuest Mini-5 Interconnects on closeout. These have a single central stereo cord that's broken out at each end with an RCA pair, perfect for sending both channels to the stereo input of the JL Fathom. These Mini-5s use AQ's best copper, PSC+, and this sale enables you to get some really long, convenient-to-place interconnects for an excellent price. E.g., 3M for $59.99 or 5M for $79.99. |
Mcpherson,
Please, no worries. Appreciate every comment members make. Where is Thor Audio located? This integrated unit has a line out, but it doesn't make enough voltage (or at least this is what I've been told by a reputable Jolida dealer) to run these JL subs. And yes, am pretty much bummed at this point trying to get some "reasonable" solution. I've finally sent off pix to Barry Oder at the Soundoctor company. He's supposedly the "go-to" guy for JL Audio home components. Will see what his comments are. Just don't want to purchase another amp/preamp at this time. Just took deliver of a new Marantz Super Audio SACD player, along with having one of their nice TT15 tables on the way from Crutchfields.....
Oldrider |
Oldrider,
I feel a bit silly that i missed the part of the original post stating that you had an integrated amp. I just looked at some images on line and i understand your delima. I was thinking you had a preamp to amp setup...so that would allow you to just split the signal coming from your pre.
Man... i cant imagine having that sub and not being able to fully utilize it!
If you really get obsessed with it maybe call Ted at Thor audio and they could probably covert your tape in to another line out as they did on my pre. Just a thought. Sorry for the confusion. |
Mcpherson,
Would you mind going into a bit more detail with this wiring idea? I'd need the male connectors to go into the left/right attachment points on the back of my JL sub, but how are you suggesting I attach to the integrated amp?
Oldrider |
Have you tried just a common "splitter"? Male on one end and two female to split the IC signal? |
Simple answer.
1. The manufacturer of the integrated amp has not chosen to accommodate a sub as an option because his market analysis told him that it was not cost effective.
2. The manufacturer of the subwoofer has not chosen to accommodate speaker level input from an integrated amp as an option because his market analysis told him that it was not cost effective.
The HT market (which is the dominant market for subs) and the audiophile small integrated amp market have almost no overlap. |
All of these "possible" corrections sound plausible. However, just wondering why it's such a "dark-science" to hook up a state of the art subwoofer to an integrated amp that "doesn't" have subwoofer outs.....
Think i'll just call this Barry guy tomorrow a.m. to see what he's come up with...Next after that will be to call JL Audio and try to speak with someone higher up the ladder....
Agh!! |
Surely, someone makes an inexpensive buffer/line driver these days. All it takes is a chip or two with connectors. Easy for DIY but I could not find one assembled from a quick Google except for car audio (http://www.hifisoundconnection.com/Shop/Control/fp/tcat/28019/SFV/30046) or (http://www.crutchfield.com/S-HM6eCZQhSQ3/p_136CLRLC/JL-Audio-CL-RLC.html) or this: http://store.arcaudio.com/p/ald?pp=8&pp=8 |
How on Earth do other people wire a sub like this into a 2-channel system? Since the sub has only line-level inputs, and not speaker-level inputs, it would normally be used either in systems having a separate preamp and power amp, or having an integrated amp that has jacks providing the outputs of its preamp section. Was told by Galen Carol in Texas (after having paid a few hundred to ship down and then back to Alaska) that the connections were "passive" and wouldn't have enough voltage to drive the Fathom i have. What are the symptoms you are perceiving? Inadequate volume from the sub? Using a passive output may or may not provide adequate volume depending on the input impedance and the voltage sensitivity of the sub (both of which appear to be unspecified), and the output impedance of the passive output (which I presume is unknown). If that is in fact the problem, a solution would be to connect those passive outputs to the inputs of a simple, no frills (but decent quality) preamplifier, and connect the preamp's outputs to the sub. The preamp would present a high input impedance to the passive outputs of your amp, so it would be easy to drive, while driving the sub from a low output impedance and providing adjustable voltage gain. Hope that helps. Regards, -- Al |
Thanks for the input. Had made contact with JL's tech line who then transferred me to a guy named Barry who supposedly knows how to make this stuff work. He was going to make contact with Jolida, but as of yet haven't heard anything back. Was told by Galen Carol in Texas (after having paid a few hundred to ship down and then back to Alaska) that the connections were "passive" and wouldn't have enough voltage to drive the Fathom i have.
How on Earth do other people wire a sub like this into a 2-channel system? 4 grand later and it makes a nice dust collector, but that's about all...
Truly appreciate your help, and as you can tell, I'm somewhat peeved about not knowing how to do this...
Oldrider |
Not sure about Jolida service or techs...but I had my Thor TA-1000 upgraded (caps, etc). Anyways while it was there, they changed the tape to another line out in case i want to run two amps or sub in the future. Dont think it was much of a process as they didnt charge me any extra to do it. Just a thought. |
The previous owner had an additional set of RCA connectors installed for running some sort of sub within his system. I've come to find out that these 2 connectors won't work with my JL Sub .... Can you provide further details on why this is so? I would expect that if the amplifier was modified to provide line-level outputs on RCA connectors for the previous owner's sub, those outputs should work with pretty much any other sub that provides line-level inputs. Also, as a point of information, there is probably an additional reason why using the tape jacks would not work, besides the one Spinaker correctly cited. On the 801A version of the amp, at least, the pair of tape jacks that is provided are inputs, not outputs. Regarding speaker-level to line-level converters, all of those I have ever seen are for lo-fi applications, such as in automobiles, and would not do justice to your JL sub. Also, many of them are not rated to be able to handle the voltages your amp may put out on its speaker connectors, without being damaged. It is possible to rig up a converter yourself, using resistors to divide down the signal level, but you may not be looking to undertake a do-it-yourself project. So I would focus on what the problem is with the connections the previous owner added. Not sure what else to suggest. Regards, -- Al |
Running any sub out of a tape out line is a terrible idea because you have no volume control. Best bet in this case as the fathoms have no high level inputs, is probably to buy an outboard speaker to line level convertor. This is a transformer that will accept speaker level inputs from your amp and outputs line level outs required by the sub |
