Crack to Speedball Upgrade: Problems with Hum and No Sound in Right Channel

TontonFlingeur · 4015

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Offline TontonFlingeur

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Hello,
I'm a newbie to the kit world.
During the Holidays I bought the Crack to drive my HD650s from my MacBookPro via a CEntrance DACPortLX.
Awesome sound, dead quiet, nice tube-y post-coital glow, couldn't want more - except that's where the addiction begins  ;D
After hearing all the great things about Speedball, I took the plunge, got the kit, and just completed the build.
Ugh!
I know I've messed up, but I don't know how to make it right.

The Diagnostics - voltages are way off (I used terminal 12 as ground on all checks):

Terminal / VDC - expected / Actual Voltage / Pass(P):Fail(F)
1 / 75 / 85 / P
2 / 170 / 77 / F
3 / 0 / 0 / P
4 / 170 / 77 / F
5 / 75 / 49 / F
6 / 0 / 0 / P
7 / 100 / 73 / F
8 / 0 / 0 / P
9 / 100 / 46 / F
10 / 0 / 0 / P
11 / 0 / 0 / P
12 / 0 / 0 / P
13 / 170 / 77 / F
14 / 0 / 0 / P
15 / 185 / 127 / F
19 / 0 / 77 / F
20 / 206 / 0 / F
A1 / 75 / 46 / F
A2 / 0 / 0 / P
A3 / 1.56 / 0 / F
A4 / 0 / 0 / P
A5 / 0 / 0 / P
A6 / 75 / 74 / P
A7 / 0 / 0 / P
A8 / 1.56 / 005 / P
A9 / 0 / 0 / P
B1 / 75 / 76 / P
B2 / 170 / 78 / F
B3 / 100 / 73 / F
B4 / 75 / 47 / F
B5 / 170 / 77 / F
B6 / 100 / 45 / F
B7 / 0 / 0 / P
B8 / 0 / 0 / P

User Impressions:
Hum - which never existed before (was always pure black background).
No sound in right channel.
Half of my LEDs are not emitting.

Any help most appreciated!

Thanks in advance.

-TontonFlingeur





Offline Jim R.

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Hi,

Welcome to the BH forum and the "addiction".

First thing to check is that all the transistors (the litttle can ones) are all in their correct places -- there are two different kinds and they are not interchangeable.  Also make sure all your LEDs are in the correct way.  These are the typical things that cause the problems you are having -- these and bad solder joints, and solder bridges on the pc board and 9 pin tube socket.

So check all that out first and then let us know what happens.  If the transistors are in the wrong places they may have been damaged, likewise with the LEDs, so if this is the case call bottlehead and they will send you new ones.

Good luck,

Jim

Jim Rebman -- recovering audiophile

Equitech balanced power; uRendu, USB processor -> Musette DAC -> 5670 tube buffer -> Finale Audio F138 FFX -> Cain and Cain Abbys near-field).

s.e.x. 2.1 under construction.  Want list: Stereomour II

All ICs homemade (speaker and power next)


Offline TontonFlingeur

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Hi Jim,
And thanks for your response. Yesterday I went through the items you mentioned in your post. The transistors (the little silver can ones and the black ones with one metallic faces) were all correctly positioned, as were the LEDs.
I then re-verified the solder joints - there were several that had grayed out, so I re-flowed those.
I then re-did the voltage check and got the same readings as before.
I continued to poke around afterwards, and must have shorted out something since there was no current. So I'll be picking up a few .5A replacement fuses today and trying again tonight.
If you have any additional thoughts around potential fixes I'd be happy to try those as well.
Thanks again for you help.
Best,
-Dave



Offline Jim R.

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Dave,

No, just make sure everything is right, including the polarity of the power supply diodes and caps, though this would hardly only effect one channel.  And just look closely again at all the connections where things are tight -- tube sockets, headphone jack, etc.  Are both the LEDs on the 9 pin socket glowing, and did you remove the 22k plate resistors?

Good luck,

Jim

Jim Rebman -- recovering audiophile

Equitech balanced power; uRendu, USB processor -> Musette DAC -> 5670 tube buffer -> Finale Audio F138 FFX -> Cain and Cain Abbys near-field).

s.e.x. 2.1 under construction.  Want list: Stereomour II

All ICs homemade (speaker and power next)


Offline Grainger49

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Dave,

Hang in there.  These things always get fixed.



Offline Paul Birkeland

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99% of the time, this is a 2N2907 and 2N2222A swapped.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline TontonFlingeur

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Thanks, all, I'll keep at!
I did replace the .5 250V fuse with a new one, and still no current, so I must have nuked something along the way.
Are the 2N2907 and 2N2222A specific to the Crack upgrade (I don't have my manuals right now)?
I'm asking because my Crack prior to the Speedball upgrade was working just fine.
Thanks.
-Dave



Offline Jim R.

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Dave,

Yes, the small transistors are on the speedball board and are only part of the speedball upgrade.  They look similar and it is easy to put the wrong one in the wrong place.

-- Jim

Jim Rebman -- recovering audiophile

Equitech balanced power; uRendu, USB processor -> Musette DAC -> 5670 tube buffer -> Finale Audio F138 FFX -> Cain and Cain Abbys near-field).

s.e.x. 2.1 under construction.  Want list: Stereomour II

All ICs homemade (speaker and power next)


Offline TontonFlingeur

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Hey Jim,
Yep, I messed up the placement of the 2N transistors, so that's good news (well, identifying the problem is good, anyway).
I'm still consistently blowing the .5A 250V fuse, though (I haven't put the 2Ns in their correct locations yet).
What I hope is my last question!
What's the best way to identify what's blowing the fuse?
Thanks again for all the help.
-Dave



Offline Jim R.

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Hi Dave,

No worries, lots of folks make that nistake -- just call bh and they'll get you a replacement out in the mail.

On the fuse, first take care of the transistors and then if the fuses are still blowing it may be that they are fast blow and they should be slow blow.

I'm guessing that the problem is either one or both of these -- transistors or fast blow instead of sslow blow fuses.  Some of the kits got shipped ith fast blow fuses by mistake.

You're almost there :-).

-- Jim

Jim Rebman -- recovering audiophile

Equitech balanced power; uRendu, USB processor -> Musette DAC -> 5670 tube buffer -> Finale Audio F138 FFX -> Cain and Cain Abbys near-field).

s.e.x. 2.1 under construction.  Want list: Stereomour II

All ICs homemade (speaker and power next)


Offline TontonFlingeur

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Hey Jim,
I think you're right about being close to the finish line!
I used solder braid to free the two misplaced silver can transistors, but destroyed one of them in the process.
Fortunately I contacted Eileen earlier today, so replacements are on their way via mail.
I bought some slow-blow replacement fuses from the local Radio Shack this morning.
So, once I get the replacement transistors from Eileen, solder 'em in, click in the fuse, say a prayer while standing on one leg, and I should find out what it's like to Speedball!
Thanks again for all the great help.
Best,
- Dave



Offline Jim R.

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Dave,

Yes, it is really easy to destroy those little can transistors when desoldering, but you'll have the new ones soon.

The pleasure is all mine -- we just do things like this on this forum, so just pay it forward when the opportunity arises.

Take care,

Jim


Jim Rebman -- recovering audiophile

Equitech balanced power; uRendu, USB processor -> Musette DAC -> 5670 tube buffer -> Finale Audio F138 FFX -> Cain and Cain Abbys near-field).

s.e.x. 2.1 under construction.  Want list: Stereomour II

All ICs homemade (speaker and power next)


Offline TontonFlingeur

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Success!
My amp with Speedball upgrade is now working!
I did a few things: replaced the LED running from the nine pin center post to A8, replaced the small can transistors (2N2907 and 2N2222A) that I had placed incorrectly, resoldered the center post on the two MJE350 transistors, and replaced the .5A/250v fuse with a new (slow-blow) one.
Thanks again for all the assistance, especially to Jim R.
Best,
Dave



Offline Jim R.

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Dave,

Congrats!  Glad to be able to help.  Now just sit back and enjoy!

-- Jim


Jim Rebman -- recovering audiophile

Equitech balanced power; uRendu, USB processor -> Musette DAC -> 5670 tube buffer -> Finale Audio F138 FFX -> Cain and Cain Abbys near-field).

s.e.x. 2.1 under construction.  Want list: Stereomour II

All ICs homemade (speaker and power next)


Offline TontonFlingeur

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Thanks, Jim, and yes I am enjoying!
I know the Crack doesn't come with pot settings, but I'm guessing I'm at 1.5/11 :) and loving life.
It's a great feeling hearing my favorite songs on this rig.
-Dave