Bottlehead Forum
Bottlehead Kits => Crack => Topic started by: Jamus on June 14, 2015, 05:52:20 AM
-
Hello fellow crack addicts. I just installed the speedball upgrade to my crack and all voltage checks were within 10% of guidelines. I should first say the benefits were very nice as advertised, faster, tighter bass, livelier sound, veil of HD650s removed. Before the upgrade the stock crack was dead silent in terms of noise floor. After the upgrade there is a noticeable hiss even at low volumes when there is a lull in the music. Also, the volume is significantly louder, can't go past 9 o'clock comfortably (7 o'clock = off). Before upgrade 11-12 o'clock was loud. I've checked all solder joints, everything seems good. Any suggestions?
Thanks!
Jamus
-
On closer inspection I noticed bridged solder joints on the left B+ pad and right G pad of the PC board (bridged within each, not across B to G, that would be a trick!). Can I assume that's expected due to their close proximity?
-
On closer inspection I noticed bridged solder joints on the left B+ pad and right G pad of the PC board (bridged within each, not across B to G, that would be a trick!). Can I assume that's expected due to their close proximity?
Bridging two pads that are electrically connected won't cause any problems.
Do your 2N2907's say "Korea" on top of them?
-
Bridging two pads that are electrically connected won't cause any problems.
Do your 2N2907's say "Korea" on top of them?
Thanks for the reply Paul. That's kind of what I figured on the bridged pads but I'm grasping at straws here.
I'm using the replacement 2N2907s (non "Korea" model).
-
Is the hiss something you notice on both channels, or just one?
-
Definitely both channels, worse on some albums that others (CDs through Marantz CD5005). I'm not sure if "hiss" is the right term, it's that background sound you would typically hear when you crank the volume to 11 when there is no music playing. Could this be related to the apparently much higher gain with the Speedball?
-
it's that background sound you would typically hear when you crank the volume to 11 when there is no music playing.
That's most likely hiss. I'd be reheating the solder joints on your Speedball boards, especially the small ones.
Could this be related to the apparently much higher gain with the Speedball?
The gain is only marginally higher.
-PB
-
Thanks for all your help. I went back and touched up all the solder joints. The hiss is definitely still there. However, it's noticeable on certain albums more than others. Could it just be that as you increase your ability to resolve the source material that the quality of the recording matters more and more? For example, one album that really stands out for having way too much hiss is Brandi Carlisle's "The Story". Perhaps that album was just not recorded very well and the hiss is just really there?
-
The second sentence of that album's Wikipedia page mentions that it was recorded on tape.
-
The second sentence of that album's Wikipedia page mentions that it was recorded on tape.
wow, well that clears things up! thanks for pointing that out!
I'm going to go ahead and say this one is resolved and I think I need to invest in some better recorded albums! (not that there's anything wrong with analog)