Impedance Matching Question

astelmaszek - thanks for your reply. That’s an interesting looking device and definitely appears that it would work, however probably more than I want to spend in this situation.


atmasphere - and thank you for your reply. I’m not concerned with elegance. I just want something that will work and sound decent. Just trying to use some extra gear to make some sound in a not so important location. Your reply did prompt me to do a little more "Googling" and I found this,

https://www.bhphotovideo.com/c/product/217366-REG/Rolls_MB15B_MB15b_Promatch_2_Way_Stereo.html

From looking at the specs for RCA, it appears that it should work, however I have no experience with Rolls products. As I said, not looking for super quality, but don’t want junk either. This line transformer sounds like a DIY project. So, is it just getting the proper transformer, 2 pair of female RCA’s, and a project box, then solder and assembly?

atmasphere - thanks for your additional info, made an inquiry to Rolls about the bandwidth, but have not heard back. The box, RCA's, solder, and assemble would be no problem, however getting the proper transformer is beyond my expertise.

George - the preamp is an old VTL Maximal with a 5K ohm output impedance. I have tried a few amps with it. One was a 75 watt Belles with a 25K ohm input impedance. The result was poor, soft, rolled off, and no dynamics. That amp sounded great with a SS preamp. Surprisingly, the best sound with the VTL has been with the 18 watt power amp section of an Advent 300 receiver, quite a bit better than the Belles on the same speakers. It's input impedance is 100K ohms, so that proved to me that proper impedance matching is important. Thanks for the links to the buffers, however as I said previously, more than I want to spend in the location.

koestner - thanks for the info, that Burson RCA cable looks intriguing. Appears that it would solve the problem and it might be entertaining trying it on some other systems I have. I sold some cables in the past year, so it's easy to justify spending some of that money on new cables. :-)

George, thank you very much for your additional comments. I was already leaning toward not getting the Burson cable. I have found that the Polk Audio RTi A3 is on closeout for $240/pr, so not much more than the cable. It got an excellent review in Stereophile and made the Recommended Components list. It also has a real wood veneer cabinet, so definitely seems to be worth the current price. I'm thinking it's 89-90db sensitivity is likely enough that I'll just use the Advent 300 with the VTL. It's a small room and I don't need extreme volume. The Advent is surprisingly strong for 18 watts. Guess it was designed to have good current output since it was used with the original Advent speaker. Thanks again for your help.

Thanks George for the iTube comments.

astelmaszek - initially I thought the iTube2 at $399 was more than I wanted to spend, however after finding a deal on the iTube for $239 shipping included, I’m thinking that’s just a little more than the Burson cable at $200 and the iTube has more capabilities than a cable. This same authorized dealer is also offering the iTube2 for $279 shipping included, so I ordered one. I’m thinking I’ll just have fun trying it in various places of my systems, and then always have a good way to use any amp with the VTL if I so desire. Thanks for your recommendation of the iTube.