If you love both the speakers (GT Audio Works have made some great ones, though I haven't heard these) and the amp, the Anti Cable Zero Autoformer seems like it could be the perfect solution. It merely raises the impedance of the speaker, making it interact better with tube amps. Maggie (3-4 ohms) owners have used them for years with great success.
Planar ribbon speaker and Tubes Not working Please help!
Hi all, I will try to make this short:
for 2 years I loved my 2 PrimaLuna DiaLogue Premium HP Amps so much that I have invest it in having 3 sets of tubes for them (EL-34, KT-120 and KT-88). I have use them to drive few speakers including a custom open baffle array I make with (12) 7" woofers and 9 BG NEO-8 tweeters each.
Few months ago I auditioned a pair of speakers that blow me away, The latest creation by Greg Takesh of GT Audio Works, a full planar speaker with a large Planar magnetic driver 10" x 72" and a ribbon tweeter .5" x 72".
When I auditioned the speakers they where using PASS XA60.8 amps.
I tried the speakers at home and with the Primalunas the sound is dull, it lack nearly all upper end detail, it sound like I put a 3ohm resistor on the tweeter.
I have a pair of more inexpensive DSonic M3-600 and to my surprise they sound as good as the Pass labs.
I already tried various cables, all 3 of the amps Tabs 2,4,8 ohm (PL amps are 2,4,8 ohm in mono and 4,8,16 ohm in stereo) and I tried all of my 3 tubes.
The KT120 improved the top end but it is still dull, the EL34 is unbearable (sound like there is no tweeter)
The speakers are purely resistive (ribbon) 4ohm, 93db.
The only think I have not tried is KT150s and changing the input 12au7 tubes to something like a RCA Cleartop ( I read in the forums those tubes are brighter.
I really need some help, or someone that can really explain why these amps are sounding so bad with these speakers.
I have used these Amps with Joshep Audio, Martin logan, Tyler Acoustics, Magnepan 3.7i plus others and they have always sounded beautiful and always a lot better than my DSonic M3-600, but with this speaker is the exception the Dsonic sound way better than the PL!.
I appreciate any comment/ help etc. At the end if I can make these amps work I will have to find them a good home and get myself a pair of PASS XA60.8.
for 2 years I loved my 2 PrimaLuna DiaLogue Premium HP Amps so much that I have invest it in having 3 sets of tubes for them (EL-34, KT-120 and KT-88). I have use them to drive few speakers including a custom open baffle array I make with (12) 7" woofers and 9 BG NEO-8 tweeters each.
Few months ago I auditioned a pair of speakers that blow me away, The latest creation by Greg Takesh of GT Audio Works, a full planar speaker with a large Planar magnetic driver 10" x 72" and a ribbon tweeter .5" x 72".
When I auditioned the speakers they where using PASS XA60.8 amps.
I tried the speakers at home and with the Primalunas the sound is dull, it lack nearly all upper end detail, it sound like I put a 3ohm resistor on the tweeter.
I have a pair of more inexpensive DSonic M3-600 and to my surprise they sound as good as the Pass labs.
I already tried various cables, all 3 of the amps Tabs 2,4,8 ohm (PL amps are 2,4,8 ohm in mono and 4,8,16 ohm in stereo) and I tried all of my 3 tubes.
The KT120 improved the top end but it is still dull, the EL34 is unbearable (sound like there is no tweeter)
The speakers are purely resistive (ribbon) 4ohm, 93db.
The only think I have not tried is KT150s and changing the input 12au7 tubes to something like a RCA Cleartop ( I read in the forums those tubes are brighter.
I really need some help, or someone that can really explain why these amps are sounding so bad with these speakers.
I have used these Amps with Joshep Audio, Martin logan, Tyler Acoustics, Magnepan 3.7i plus others and they have always sounded beautiful and always a lot better than my DSonic M3-600, but with this speaker is the exception the Dsonic sound way better than the PL!.
I appreciate any comment/ help etc. At the end if I can make these amps work I will have to find them a good home and get myself a pair of PASS XA60.8.
8 responses Add your response
I already tried various cables, all 3 of the amps Tabs 2,4,8 ohm (PL amps are 2,4,8 ohm in mono and 4,8,16 ohm in stereo) and I tried all of my 3 tubes.Have you tried triode mode? John Atkinson’s measurements of the non-HP version of the amp indicate output impedances in ultra-linear mode that are extremely high, while being considerably lower in triode mode. As others have alluded to, high amplifier output impedance = reduced highs if the speaker’s impedance is lower at high frequencies than at lower frequencies. Good luck. Regards, -- Al |
Tubes + ESL's...Not good! ESL's can dip to 1/2 an ohm! They need pure solid state muscle to drive them correctly...Your PL's don't have it.Just a FWIW- in this case a magnetic planar is being used. @audiogurujax I would see if you can borrow a set of ZEROs (www.zeroimpedance.com) and see if they solve your problem. If so then we can conclude that the speaker's impedance curve goes lower than you think. |
Are you certain the impedance is that high? Your comments suggest that the tweeter impedance is lower than you think. Check the speaker and see if there is a choke in series with the woofer panel. If not, its impedance is in parallel with that of the tweeter. So while it may be 4 ohms in the bass, it might be 2 ohms or less in the range of the tweeter. 4 ohm speakers are far more critical of the speaker cables. If your prior speaker was 8 ohms, it might be that the cables you have now, while working perfectly well with solid state amps, don't do so well with a tube amp, which has a higher output impedance. I would therefore try different cables and if at all possible, keep them really short! Its not so important with solid state amps but with tubes it is. |
