A Few Small Post-Build Issues

[williaty]

To clarify, the rushing noise, or maybe it's a hiss, I dunno, is present with an input connected or with them shorted, but it's at a low enough level you can only really hear it when there's no signal playing. With music playing, it just lends there sort of odd gummy weight to the right channel. That's an exaggeration, it's a subtle effect, but that's the only way I can think to describe it.

It's really weird to listen to right now. There's so many more sounds and details and whatnot that I can actually identify. All the lower sounds are just MUCH better controlled as well. Yet there's this sterile lifelessness, dryness, brittlenees, something, to it that just makes it sad to listen to. It's the same sort of sound you got out of a cheap solid state amp during the late 80s/early 90s when everyone was chasing the "lowest THD ever!" in consumer gear. It's a weird mix of considerably better performance and yet at the same time less good at being music.


I must have screwed something up.

[williaty]

OK, a couple of more hours and some frantic searching for different tubes...

Nearly smashed in the back of the junk drawer I managed to find a 12AU7 someone had once given me to make a necklace out of. Thankfully, I'd never gotten around to it!

So, first things first, the odd rushing sound was caused by the Electro-Harmonix 12AU7 included with the kit. I have no idea why it only manifested itself after the Speedball upgrade, but there it is.

Sound wise, well, it's a different mixed bag. Switching to a different tube definitely removed the sterility/dryness. Most of the boogie is back. On the other hand, things sound just a tiny touch... muddled or confused. Let me place that in context by saying it's still more clear and organized than any other headphone amp I've ever heard and is arguably more sorted out than pre-Speedball, it just loses a tiny something in comparison to the EH tube post-Speedball. On the other hand, it's fun to listen to it now so I'm not going to obsess over this.



Oh, the tube I dug out of the back of a drawer, all scratched up? Turns out it's an RCA Clear Top! Started googling for what "A Electron Tube" might be. Added words like side getter, etc. Finally saw a picture and realized that the "RC" had scraped off, leaving a big A next to the stacked "Electron Tube". Nice sounding tube.

[Grainger49]

I've got a packet of resistors left over from the Sweet Whispers build 10 years ago. I'll see if any of them come up useful.

I think those are too low a resistance to be useful padding your volume control unless they are the series resistors for matching the SW to your system.

Give the Speedball a break in and all sorts of music.  As for the rushing sound, you have lowered the noise floor to the point you probably hear the tube rush.  Swap tubes and you should find the rush in the left channel.  That is the tube.

[Laudanum]

This is kinda why I havent jumped on trying Speedball yet.   Im just really enjoying the Crack as is.  I havent had the itch to upgrade anything other than roll tubes.  Im not sure Im really in search of added detail or clarity as I dont want to move closer to what I may perceive as a more "sterile" or SS sound.  And the background is extremely quiet as is.  The temptation is there more for the ability to be able to roll a couple more tubes and I may end up loving what Speedball does even more, afterall it does seem that the vast majority hail it as improving Crack even further.   But Im finding myself enthralled with an Amperex 12AU7 ( GE and Triple mica 5814's are in the running as well) and a Tungsol 5998 right now.  Im sure I'll probably try it down the road, as it is easily reversible.

[Grainger49]

The Speedball is going to reveal more music than noise.  If you have a tube that has some noise when you turn it up you will hear it if you didn't before because it was buried in the noise floor.  There are benefits and problems with improving your system.  As the resolution increases some things are exposed for the nasty things that are there.  A bad tube, or a less involving tube is exposed as such.  Good, involving tubes are exposed as that as well.

So don't throw the baby out with the bath water.  The Speedball upgrade isolates the power supply noise from the audio path.  It should be cleaner but more detailed.  That isn't really SS sound but more revealing sound. 

[williaty]

Through how many dB does the volume pot turn? I'd like to add about 180* of travel to it, so if I know about how many dB of attenuation 180* represents, I can just pad it that much.


I'm still not sold that the Speedball actually moved the sound in a direction I like. Even with the Clear Top in there, it's still awfully dry and makes it boring, for lack of a better description. I'd really be interested in wither there's something I could have screwed up to make it sound like this. Given that I trust Doc B, PB, and the rest of them, I'm operating under the assumption that the Speedball is good and I made a mistake somehow.

One thing I did have to do was to "remote mount" the coupling caps. With how I'd run the wiring, there wasn't enough room to just push them flat and then install the Speedball board. I de-soldered them and put them on the ends of 2" pieces of wire. Could that be making the sound change? See the picture:
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Ffarm3.static.flickr.com%2F2720%2F5851707087_bc272a1844_b.jpg&hash=eb4512f8eda6b2ce121c3f58ad829b499242c86d)

[Laudanum]

I like the Cleartops in an el84 based amp I have.  But dont really like them in Crack with several different 6080-6AS7 tubes including 5998.  It could be your tube synergy to a point as well.  I never really found a GE tube that I liked in my other gear.  But I like the GE 12au7 in crack, a close second to the amperex. 

BTW,  I wasnt dismissing Speedball by the way.  Just living with the stock amp right now and very happy with the sound.  Im not in a hurry to upgrade.  But Ive been like that with several kits.  I never upgraded a phono stage I built when upgrades  became available just because I was happy with it as is.  I guess Im just not the type that always looks to upgrade.  But again, Im pretty sure that I will end up trying speedball in the future.   

[dubiousmike]

When my crack was still stock, I found that my clear top had a pretty nice synergy with the sound signature of my HD650's.  My perception was that it added a little bit of brightness and bite to the top end that was welcome with that headphone in particular.  When I later upgraded to HD800's, the clear top had to go.  (The presentation was overly bright and stripped violins and trumpets of some of their texture.)  With my speedball now in place, I'm running (and loving) a 12au7 amperex bugle boy, with a 5998 in the rear (like Laudanum), and the sound is absolutely glorious. 

If I could get rid of the minor hum, I think I might like a 1950's rca 12bh7a "black plate" nearly as well, but with my current phones, the amperex tube is much more enjoyable (to me) than my other 12au7's (or, for that matter, the 1960's rca 12bh7a "grey plate" I also have on hand).  I still really want to get my hands on a mullard long plate though as I suspect it would give the bugle boy a run for its money.

With respect to the speedball, I totally agree with Grainger's description.  The sound is just a bit cleaner, tighter, and more detailed, particularly in the low end.  I didn't notice any loss of warmth at all, but well recorded string bass sounds even better than it previously did - which is really sayin' something! 

[Laudanum]

hopeful ... that's good to hear about speedball, more reassurement (is that a word?).   As far as tubes, I have a couple of Mullard short plates but no long plates either.  I need to roll a short plate Mullard back in because I didnt spend too much time with them.  But I think the Amperex is the ticket.  But the GE 12AU7's I tried and also a some JAN 5814's werent far behind.  Different but also pretty darn good.

[2wo]

You might be due for an output cap upgrade. There is a thread going on now...John

[williaty]

Mea culpa, mea maxima culpa!


Well, it turns out it *was* something I screwed up, but COMPLETELY un-related to the Crack and Speedball. Turns out, it was a computer change that just happened to take place at the same time as I was putting together the Speedball upgrade. In MacOS, there's aparrently several ways of getting data from a player to the audio output device. One of them is clearly labeled "More Magic" and the other is obviously labeled "Less Magic". Depending on the order of operations of how different programs access CoreAudio in order to do things like play sound effects, music, movies, etc, the audio pathway can be kicked into More or Less Magic. This explains my bipolar feelings about the setup overall; when I was sucked into listening and let it run for album after album, it happened to be in More Magic. At other times, when it was flat, harsh, and unlovable, and it just left me confused and depressed, it was in Less Magic. Tonight, I discovered a piece of software that will force the system into the More Magic pathway for the duration of listening to music and then return the computer to normal operation when I close iTunes. The result?


Wow... just... wow.

[Grainger49]

A-ha!  It is an Apple thing, the iFracked!  Reminds me of the email I got yesterday mentioning an iPod aimed at young children the "iTouch Kids" which they decided against after reading it outloud.  (just a joke)

[Laudanum]

Ah, computers.  Cant live with them, cant live without them and cant afford to replace them if you empty a 9mm magazine into them :-P

[Jim R.]

So, what is this magic utility?  Are you talking about HOG, or exclusive use mode?  If you really want to kick it up, try the PureMusic player:

http://www.channld.com

Still uses your iTunes library and database, but PM intercepts the playback and sends it out a much higher quality playback engine than QuickTime, which is what itunes uses.  The demo is free and runs for 15 days after install with no limitations.

There are also quite a few background process in OSX that you can turn off and that have a positive effect on playback quality.

-- Jim

[williaty]

I'm using Bettersound now. No way I'm paying for PureMusic, Amarra, etc.