e-Lips

richidoo · December 23, 2010, 01:46:31 PM

Sol has some new improvements for the i60 so it "met its maker" today.

While here, Sol looked for the source of some mild hum (-70dB or so) from my 300B amps. No ground loops were found, and it's near dead silent when the amp's front panel input mute switch is activated. We tried swapping ICs to Belden 1505 which is well shielded, no difference, even shorted. So we think it might be the internal input wire routing past the power tranny in the narrow case on its way up front to the mute switch and input circuit. The input wire is Van den Hul shielded wire, but it might need even more shielding because it passes within 2 inches of the power transformer. It is 60Hz and 120Hz EMI that we hear. The input tubes with gain are in front, at least 12 inches from the power transformer, with output tran and PS caps between, so it should be quiet enough up front. Any ideas how to shield the input wire, or replace it with better shielded wire?

I took apart the crossover system, and connected the Buffalo32 direct to 300Bs with my old JPS UC ICs and straight to the Feastrex in OB with JPS SC3 wires. Parallel single ended mode with 5db NFB... Wow, that is music! There is enough midbass to enjoy the music, but nothing low. It's good enough til Santa gets here with my Rane!

richidoo · December 28, 2010, 09:43:08 AM

OK, now we're cookin. The Rane is hooked up and adjusted to a basic working setup. With 4th order crossover, some baffle step it sounds pretty good. No other EQ yet. Low bass and upper mids still need EQ.

The funny thing is that I adjusted it to my own taste last night, which turned out to be very bass light. To make Carl's test tracks sound correct (Alice In Chains) I had to crank in 6dB more bass!

Now the system sounds huge and very powerful. Solo cello sounds better too... thanks Carl!

The Feastrex is hangin in, but it needs EQ in the mid and upper mids to chill out a bit. It has always had that forward sound, which is very appealling on acoustic music at softer volumes. With EQ I think it will be fine. It can play loud.

The AE drivers are extremely good, the louder they play, the better they sound. stereofool's Audio Research VT100mk3 is powering them now, and they are slamming.

The Rane is infinitely adjustable. There is a lot of potential in fine tuning the whole system. The sound quality of it is OK. I can hear the 47uF electrolytic coupling caps in the signal path, and JRC 4580 opamps, but those can be upgraded pretty easily. As expected, it is not as refined and smooth as my DAC, but about as same as the modded Behringer - not too bad. I'll look for a way to get the digital directly from the processors.

But I'm glad to finally hear the speakers making full range music. I'll have to get out the mic and measurement software to fine tune it further.

bpape · December 28, 2010, 10:17:13 AM

Do you feel like a little kid again? Knowing what your present was and not being able to use it until after Christmas

Sounds like you're just having way too much fun Rich.

Bryan

richidoo · December 28, 2010, 11:25:19 AM

Yes, indeed! And not just that, but now that I've opened it I realize there is a learning curve that will take me all year to master, just like a video game or a 300 in 1 electronics kit. It's an educational toy!

Fun yes, but I found a new meaning for listening fatigue when trying to EQ the system. Every song needs a different mix to sound best. Finding a good one in the middle is tough! Analysis software is required to go further.

richidoo · December 30, 2010, 05:42:10 PM

Made some good progress today EQing the crossover. I think the bass EQ is done. Lots of boost, low crossover freq. It sounds good on rock, symphonies and jazz combos. It's pretty dynamic, considering the Rane box is in the middle of it all.

The midrange is proving harder to fine tune. I think the ceiling reflections are making it harder than it really is. Same old room shouting problem I've always had.

The treble was pretty easy with a simple shelving filter.

I used RoomEQWiz today to measure the Feastrex driver up close. It definitely is a full range driver.

The speaker has plenty of power for fireworks. Symphonies can wail, heavy rock is no problem. But making it sound natural and smooth top to bottom while retaining the life and dynamics is harder. Refinement will take more time.

Looking at the speaker's in room response with REW didn't help much. Combing obscures the details from 500 on up. I can smooth it, but if I EQ it flat including the room echos it doesn't sound very good at all. I think it will help to get some good ears over hear who can help EQ the midrange. The Feastrex sounds great when played full range without any EQ or electronics. So I wonder if some of what I'm trying to fix is being caused by the fixing tool itself, the Rane. I'll listen to Feastrex by itself without Rane again tomorrow.

The Rane allows me to hear various crossover options, and a simple crossover does sound very good, so I think I can then move the design into a passive crossover which will get rid of the influence of the processor. Or at least an active analog line level crossover.

richidoo · January 01, 2011, 09:51:40 PM

Did a dumb thing tonight... I was having trouble EQing with the parametric equalizer processing blocks, so I thought I'd redesign the signal path to use 30 band graphic EQ instead. You can change settings on existing processing blocks on the live unit, but to change processing blocks requires loading a different config into the unit from the PC. I didn't upload my presets from the first config back to the PC before I downloaded the new config, so I lost all 7 presets. #6 actually sounded pretty good! I remember most of what I did, but the midrange fine tuning was lost. drat!

It was listenable but far from perfect, so no biggie. Now I know how to save.

richidoo · January 02, 2011, 01:04:59 PM

Well I guess it was a blessing in disguise. I started over again this morning, swapping out the Feastrex tube amps for the current source amp, it works better. The Feastrex FR flattened out and sound relaxed. Single driver speakers really want current source amplifiers. Where the tubes needed 5 filters, the CS amp needs only one notch. Getting closer - and saved to my PC.

Carlman · January 02, 2011, 01:08:17 PM

Man, that is awesome.. Are you actually enjoying music again?

Face · January 02, 2011, 02:13:01 PM

Nice!

richidoo · January 02, 2011, 02:54:44 PM

Quote from: Carlman on January 02, 2011, 01:08:17 PM
Man, that is awesome.. Are you actually enjoying music again?

Quote from: Face on January 02, 2011, 02:13:01 PM
Nice!

Thanks guys! Yes I am enjoying music, finally! Especially today I listened to the 2nd whole movement of Beet 9th, and found only mild tonal aberrations, nothing too distracting. Finally killed a resonance in presence range without killing the presence. That took some time. I'm still in tune the speakers mode, but I thought today, "this isn't bad."

I've been playing all my big bass Reference Recording classical CDs, they really sound great with the spacious presentation of the OB. I am always tempted to turn up the bass for those, but then when I play rock tunes the bass is too loud, so I turn it down for the rock stuff. Funny huh?

Another week of fine tuning and it should be safe for masochists to come listen.
Rich

richidoo · January 06, 2011, 01:31:45 PM

I retract that last statement. It is not ready. I got pretty frustrated with the whole thing last 2 days. I would listen in the morning to the same settings that I worked on night before and let's just say it was not as good anymore.

Today I started being a bit more ham fisted with the EQ controls, and starting to see that stronger adjustments are needed than what I have been doing. The nice thing is that the Rane provides any adjustment, live, right from my laptop. Convolution filters don't allow that. I am using the presets much more now too. That allows quick A/B at the touch of the mouse, with only a quiet voltage snap.

I also put my AudioSource 80W amp in place of the tube bass amp. The lower impedance sounds tighter and the SS amp doesn't complain when tortured. Below 200Hz it works better. As much as I love tube powered music, I also like having the system on all the time, and not cringing when I remember the tubes have been running for 6 hours with nothing playing.

I also put the high resolution wires on the bass and the lesser wires on top, both SC and IC. Seems to be better synergy, at least until I can get the EQ worked out.

The bass drivers' paper cones are warmer than the Feastrex' at the crossover frequencies. So changing the crossing freq by 5Hz is plainly audible difference in tone. This affects what slopes I can use without coloring the mid bass.

The Rane is a very powerful tool. At first I was thinking that the sonic deficiencies of my first attempts at tuning the speakers were due to the Rane's pro audio breeding, opamps, etc, but now I realize that I have a ways to go to reach its potential.

Each part of the system has great strengths and some weaknesses. Blending them together into a seamless whole that maximizes strengths while minimizing weaknesses is definitely a challenge. But it is fun.

richidoo · January 06, 2011, 06:30:27 PM

Good sign...
I actually sat in front of the stereo for several hours today, listening to classical without thinking about or noticing the sound. When I concentrate I can notice some sins of omission, and it's a little soft (TWSS) but listenable without causing anxiety. Feels good.

stereofool · January 06, 2011, 06:55:05 PM

Keep going...you will get there

!

tmazz · January 06, 2011, 09:11:25 PM

Quote from: richidoo on January 06, 2011, 01:31:45 PM
....... As much as I love tube powered music, I also like having the system on all the time, and not cringing when I remember the tubes have been running for 6 hours with nothing playing.

Given that statement you should really give some thought to trying a hybrid amp like the Moscode. It gives you the flavor of tubes without a lot of the headaches. All of the tubes are small signal driver tubes, to they don't take the beating that a set of power output tubes does and even when you do have to replace them there are not that many of them and they are comparatively inexpensive, so you don't have to sweat too much about leaving them on. Except for July and August when I was trying to cut down on heat in the room I left my Moscode 600 on 7x24 and I only replaced the tubes every 3 or 4 years.

richidoo · January 07, 2011, 07:56:00 AM

Thanks Tom. After hearing the new 402 the Moscode is definitely in the running for any new amp decisions I make, but only if the speaker needs that much power. My next speaker will probably be 95dB min 6ohms. But the speaker after that is 95dB min 2.8ohms which should be perfect for Moscode (or DAC Cherry.) I like to plan ahead...