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Impedance Matching - Tube Amp/Speakers

Hi, I am not technical guy, so excuse my questions. This weekend my friend did check bias on my VTL ST-85, which I recently did buy, and he also measured my speakers Dunlavy SM-1. Multimeter showed him that they are 4 ohm spekares (althought, on paper, they should be 6 ohm). He told me that this is not good combination - 4 ohm speakers and tube amp. So, is it safe using VTL ST-85, or tube amps generally, with 4 ohms or 6 ohms speakers? I am really confused because I like sound, but also dont want damage my amp or speakers.
arzach
ts0711
91 posts
 
You’re safe…

Back in the day, I had Duntech Marquis and had lots of fun using QuickSilver Silver 60’s (KT88’s) and the Silver 90’s but those were big 3 way, time aligned speakers that really needed solid state to sing. They sounded very good with tubes but they were unstoppable when bi-amped with 2 McIntosh 7270’s .

The bass coming out of the ST-85 should be very good, although EL34’s are considered leaner than some other tube types (i.e. 6550’s), however there is always a trade-off. I currently have a VTL IT-85 (same amp section as the ST-85 using EL34’s) driving Dynaudio Special 25’s ( 4ohm, 88db) and the bass is killer.

It could be the source and or wiring.
arzach OP
4 posts
 
Hi, Ts0711, I think source and wiring is respectable (Bryston, Cardas, Kimber), only preamp is a little behind (Hitachi), but I want change tubes. Which brand tubes are in your IT-85? Do yout think better tubes can improve bass and speed?
ts0711
91 posts
 
I believe I'm using Electro-Harmonic EL34, that were sourced from VTL. In my experance different brands of tubes (in the same family - i.e. EL34) will have an impact on bass, but not speed. For my main stereo I use NOS Mullard XF2's (EL34's from the '60's / 70's) which have a fantastic bass rendering however they cost as much if not more than the amps they are in (VTL Compact 100's).

For speed and dynamics I strongly recommend "Crimson Music Link" speaker wire and interconnects... Start with the speaker wire and you will be blown away. Switching from Harmonic Tech Pro 9+ speaker wire to the Crimsons was like buying new speakers. I was amazed at the difference in PRAT that my Dynaudios delivered.

Good luck.
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