It's Alive!!!

adydula · 1353

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Offline adydula

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on: March 27, 2018, 09:54:00 AM
I started this new thread because I didnt want this "buried" in my Mainline build questions....

OK, I have 12+ headamps, three Dacs, a zillion tubes, and several media player/servers well as having a dozen headphones
of all types over the past few years.

My tastes have driven me to Beyerdynamics T90's + T1's, yes even with those mediocre reviews about their being shrill etc...

Most of the time I find the source material and how its recorded and mixed has more to do with this shrill sound than the transducer itself with the Beyers.

That said I spend a lot of time looking for recordings that are indeed the best of the best....and stopped trying to find a setup that will fix something that was done crappy with
the actual amount of eq'ing etc can fix these things IMO.

So the MAINLINE !!

It took me a week of 4-6 hours to complete. Taking my time, chceking all the solder joints, measuring resistors, walking away and checking parts placement and directivity etc..
I actually found one resistor in the wrong location on the c4S boards! Glad I found that....the only confusing part to "ME" was these smaller pc boards, you build two of them clearly
stated in the instructions, but they install in the A side and C side exactly upside down from each just be careful here...maybe its just yours truly!! LOL.

The kit had 49.9K resistors instead of 49.9 ohm resistors, a missing fiber shoulder washer, and missing 4 of the larger #8 screws that hold down the middle power reg board.
Thanks to Josh and the Queen Bee in getting this sorted out, it was a long wait here!! But it was worth it!

The tubes glowed first time, voltage checks were spot on and the biasing was set to 145 volts....with the pots in the middle of their range, the initial volts showed 180 volts or so.

There was a small high frequency noise when first turned on with headphones, some of my less expensive ATH M50's...but after a fw minutes warmup it went away..probably those tubes
waking up for the first time!..My 12AU7 has CONN on it...must be a old Conn Organ variety! Very musical!! Ha!

I checked all the inputs, switches less the balanced headphone jack, my cans are all SE.

The fit into the locking SE jack is tight, firm, etc and take some effort to remove, I imagin over time this will loosed up somewhat.

The 4 coats of the Tung Oil high gloss loks great to me, smooth and very nice IMO.

So how does it sound? 

First impressions, subjectively tells me this is indeed a very, very wonderful amp.

Musical, with well recorded stuff its magical with my T1V2's...some complain about the soundstage of these Beyers, but OMG its really
very good with this amp. (Am driving it with a Schitt MB Bimby dac). I will play with the other dacs I have in the coming days.

From listening to my Crack w/speedball and Schitt Vahalla 2 (OTL), I am experiencing a new level of listening doubt about it...

Open, Airy, tonality, all those glittering adjectives apply here....not syrupy to me at all....whats in the music comes out, good and bad.

I like many of you probably have some really stellar music, that we like and is recorded and mixed very well....and this stuff really shines.

Seeing into the music, tonality and soundstage with this amp is superlative.

I have not heard these T1's sound as good or perform as well as with this amp period.

I am glad we went thru the Crack stage, but if I had to do it all over again I would just jump to the Mainline and forget looking for something better..

This amp to is that good...

Well done Bottlehead!!


Offline adydula

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Reply #1 on: March 27, 2018, 10:55:41 AM
Well the Mainlne is making it easy to test out two different source's with the flip of the input switch!

Have my main PC, Jriver and Foobar2000 to a Schitt Bimby Dac to one input and a HP laptop to an ODAC to the other input and after level matching I can
listen to the same song at the same timeframe and flip back and forth and see what the differences are if any....

I like this.


Offline adydula

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Reply #2 on: March 29, 2018, 02:56:37 AM
After two days and about 4-5 hours of being on...I measured the bias and it dropped to 133volts.
Re-adjusted to 145 volts.

I do the biasing after the amp is on for 30 min or more...

Most likely this is normal..still sounds real good

« Last Edit: March 29, 2018, 03:01:17 AM by adydula »

Offline ALL212

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Reply #3 on: March 29, 2018, 03:59:17 AM
Nice!  I think you'll really enjoy the Mainline.

Aaron Luebke

Offline adydula

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Reply #4 on: March 29, 2018, 11:01:28 AM

How can you tell!

Yes, its a great amp....being a DIY person and liking to build stuff, solder and try to understand circuits make this project a more full-filling one vs just buying stuff and pluging it in..not that there arent many other amps that are very good as well with and without tubes.

I grew up in the 50's/60's and in college we drew load lines and learned about those new fangled germanium transisors that Bell Labs was tinkering with!

When tubes faded, no pun intended, and SS became the in thing I left the tubes behind thinking all that could be done with that technology was over and in 2018 and a few years prior I have re-discovered those old tubes can still provide a really great audio experience in a wide variety of products...