European Triode Festival 2015

For the first time since 2001, I went to the European Triode Festival, ETF. This year it was in Tisvildeleje in Denmark, and it was a great success. Five of us from Norway drove for 8 hours with three cars full of horns and tube amps. And one of us took the plane from Bergen.

Since the festival has been well covered by Thomas Mayer starting here (with mentions of our system here andhere), I will not try to cover everything. So this blog post will mainly cover the system we set up in the room we had. 

Below is a picture of the system on Thursday afternoon. Thomas Dunker is writing up the details of the system on the whiteboard. 

A block diagram of the system is shown below (click on the image for a larger version). Thanks to Lars Tørresen for the drawing.

Sources:

• Modified Dual 701 turntable with a SME II arm and a Denon DL103 pickup (Thomas Dunker)
• Micromega Minimum DVD player as CD transport (TD)

Preamps:

• Allen Wright style RTP RIAA (Bjørn Kolbrek)
• Modified Behringer DCX2496 with external linear power supply, input selector, passive analog stages and output volume control (BK)

Power amps:

• Kenwood KA-9100 for bass duty (TD)
• 300B Push-pull amps for midrange duty (BK)
• 809 SE amps for tweeter duty (BK)
• SE 801A amps (midrange, not used due to technical problems, TD)
• SE 46 amps (tweeters, not used, TD)

Speakers:

• JBL 4560 cabinets (TD) with JBL woofers by Torbjørn Lien. The woofers were a hybrid design, described by Torbjørn as "the same diaphragm as 2220-D130, magnet as D130 but with a copper voice coil, overhung, 1/2" long, i.e. the exact same motor as D140."
• "Tentamenshorn" midrange horns, as described here. These were Thomas' horns, with his modified drivers. More about that later.
• Downscaled Iwata horns (1") with TAD 2001 drivers (TL)
• Dipole tweeters with DIY 19mm 9µ titanium foil diaphragms (TL)
• Modified Coral H100 tweeters (TL)

The tweeters were crossed in passively, and mostly provided some "air". 

Several people asked for drawings for the midrange horns. We hope to be able provide that, but the drawings we've got need some work before we can make them publicly available. Please be patient. 

Thomas had brought two pairs of modified Altec 288B: one pair with Neodymium magnets, giving a gap B of 2.15T, and one field coil pair that were finished just in time to ETF. We played on the first pair until mid-Friday, then we switched to the field coil version. There was perhaps not a great difference, but at least both drivers sounded great! And the FC drivers look cool too. After some hours they were not so cool, though...

Friday evening we had live music.

The system of our room mates: Thomas Mayer (amps) and Wolf von Langa (speakers).

We were not the only ones to bring measurement gear.

On saturday, Thomas Dunker and I also held a lecture on horns and horn loading. This was a quite basic lecture on the horn design philosophy of the 1920s and the benefits of horn loading, using our big midrange horn as an example. 

Saturday evening we listened to Charles King's tapes for what must have been several hours. His Stellavox tape machine and low-generation tapes sounded magnificent and gave us a sound quality experience we will not soon forget. 

Sunday, and time to leave.