Crack;Bottlehead OTL - Page 95

Quote:

Originally Posted by Amarphael 

I have an oppurtunity to  replace the output caps with 630v/10uF paper-in-oil Ampohms. They're 65mm in diameter and 95mm in length.

10µF is far too small for the output caps. Your corner frequency with even 600ohm phones will be into the audible range (26.5Hz), meaning you will get pretty bad deep-bass roll off.

Switching in, say, 300ohm phones in the future will be even worse, pushing the corner frequency to 53Hz.

Quote:

Originally Posted by Amarphael 

Thanks for the heads up Beefy. Could you please enlighten me as to what formula I need to calculate the corner freq?

http://www.muzique.com/schem/filter.htm

The amp specifies 100µF, and you should try to stick to this value. 

Great. Does paper-oil caps are any "better" than other types of film caps for this application? 

Btw, do yo mind (or anyone) linking me to a nice budget cap, up to 10$,  from a retailer who does intl' orders?  

Quote:

Originally Posted by Amarphael 

Great. Does paper-oil caps are any "better" than other types of film caps for this application? 

 

Btw, do yo mind (or anyone) linking me to a nice budget cap, up to 10$,  from a retailer who does intl' orders?  

You are not going to find any 100uF film cap for <=$10.  The cheapest I've seen was some AXON caps from Canada that ran about $25 each, but are no longer available.  You could parallel a 75uF and 22uF though, if you have the room.

http://www.partsconnexion.com/capacitor_film_axon.html

Quote:

Originally Posted by BmWr75 

 

You are not going to find any 100uF film cap for <=$10.  The cheapest I've seen was some AXON caps from Canada that ran about $25 each, but are no longer available.  You could parallel a 75uF and 22uF though, if you have the room.

 

http://www.partsconnexion.com/capacitor_film_axon.html

The Solen PA series at 91 or 100µF are virtually identical, and not much more expensive; people were buying the Axon instead because they were so cheap. But the Solen are now also OoS at PartsConnexion...... :(

Nobody has experienced the bottlehead S.E.X vs Crack + Speedball upgraded ?

Those 75uF Axon's are doing 3.5hz corner freq by Beefy's link so i'm pretty fine with that. However is that the final load the amp sees? How is the interaction between the 'phones load and output resistors is figured, Is it combined or substracted from each other? Can't i play with the output resitor value to adjust to the Ampohm' btw?  

Quote:

Originally Posted by Amarphael 

Those 75uF Axon's are doing 3.5hz corner freq by Beefy's link so i'm pretty fine with that. However is that the final load the amp sees? How is the interaction between the 'phones load and output resistors is figured, Is it combined or substracted from each other? Can't i play with the output resitor value to adjust to the Ampohm' btw?  

Good point, the bleeder resistor does have to be included for things to be accurate. This resistor makes less difference on typical 300ohm phones, so I completely forgot about it.

The parallel resistance of the 2.49kohm and 600ohm phones decreases the apparent load to 483.5ohms. So your corner frequency is 4.4Hz. This is better than for a 91µF cap and 300ohm phones and should be AOK.

Hey all! Considering a Crack + Speedball and am wondering if anyone here has heard it compared with the Burson Soloist amping the HD-650? Any impressions on how the two amps stack up against each other out there?

Quote:

Originally Posted by dpippel 

Hey all! Considering a Crack + Speedball and am wondering if anyone here has heard it compared with the Burson Soloist amping the HD-650? Any impressions on how the two amps stack up against each other out there?

I have exactly that set of gear.  They've got their differences, as should be expected.  The best description I can give is "analog versus digital".  I'd compare the Soloist to listening to an SACD... very detailed, clean, precise and exact.  And likewise, I'd the Crack + Speedball to listening to vinyl... not as precise (but that's part of the charm), more warm and more fun.  I haven't gotten too much into tube rolling and I imagine there's a world of discovery in that, but I'm resisting the urge for the moment.

They both have their strengths and shine at different things.  In general, I think the more analog/acoustic the recording the listen to, the more I'll favor it on the Crack+Speedball ... and the more digital, the more I'll favor the Soloist.  That said, there's a heap of overlap where I'm happy both ways (like the Stevie Wonder stuff I'm listening to at this given moment via the Crack + Speedball).

My Soloist gets more use because the HD650 already has some warmth to it and I like the added detail.  I also always use my Denon AH-D2000 via the Soloist and never the Crack+Speedball.  It's simply a more versatile unit... but it also costs like twice as much.

I wanted to have both solid state and tube options to play with, and I'm very happy in both cases.  Having one is not like having the other... so if you already have the Soloist and also want a tube amp, I certainly wouldn't discourage it.

Edit: Just wanted to add that while the Soloist seems like it has more detail, the Crack+Speedball seems to have more depth.

Thanks a lot for your impressions. They pretty much echo what I'm experiencing with the Soloist and the Lyr, although I don't feel that the Schiit has more depth than the Burson. I've been pondering a Crack + Speedball for a while now and was wondering, if it was closer to the Soloist than the Lyr, if it would be worthwhile to grab one and give it a go. The Soloist certainly is a clean power beast (besides being HUGE), but as you mention it's twice the price. Decisions, decisions!!

Quote:

Originally Posted by Hun7er 

Nobody has experienced the bottlehead S.E.X vs Crack + Speedball upgraded ?

I've built both. Really, they're meant for different sets of headphones. Crack runs well with all the high impedance stuff. Sex does well with all the lower ones. Granted, at the time I compared them the best I had was a Sextett and a Beyer DT880 for high impedance, and a whole gamut of mid-fi low impedance ones.  

Quote:

Originally Posted by dpippel 

Thanks a lot for your impressions. They pretty much echo what I'm experiencing with the Soloist and the Lyr, although I don't feel that the Schiit has more depth than the Burson. I've been pondering a Crack + Speedball for a while now and was wondering, if it was closer to the Soloist than the Lyr, if it would be worthwhile to grab one and give it a go. The Soloist certainly is a clean power beast (besides being HUGE), but as you mention it's twice the price. Decisions, decisions!!

The Lyr is a hybrid amp and definitely has some tubey goodness... but not to the amount that, say, Schiit's Valhalla did when I heard them side by side.  I'd sooner compare the Crack+Speedball to the Valhalla than to the Lyr.  Makes sense... they're both high impedance loving OTL amps.

To circle back to your question... the Crack+Speedball would be more like the Lyr than the Soloist.