Bottlehead Forum
Bottlehead Kits => Crack => Topic started by: Crackhead on July 05, 2015, 04:22:05 PM
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Hi everyone, embarrassingly I am on about my 3rd round of trying to get my Bottlehead crack working with the speedball upgrade. It worked fine before without the constant current source but I botched the speedball the first time around by lifting a trace on the big board. I have since gotten a replacement and installed it. After installing a new speed ball properly my 5 watt resistor smoked and the ceramic housing disintegrated. Also I am only getting about 13 Volts from Terminal 1 and about 40 from terminal 2 :(
The worst part is that I am an aspiring electrical engineering student (still in Community College) and all of this seems like a bad omen for my career... J/K...
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fs21.postimg.org%2Fdrchu0vs7%2FIMG_3548.jpg&hash=0451185bea31160360c9ea3f4103d68936a1be70)
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fs21.postimg.org%2F51k06x3on%2FIMG_3550.jpg&hash=342140a9ccdaf42a463e01b567407cf1db1a992c)
Thanks in advance for any help you may be able to proffer...
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I suggest not powering up the amp again until you have some instruction from the Bottlehead team. If you could post some more pictures of the hooking up transformer tube sockets rectifiers etc that's going to be helpful.
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Did you install the TIP50 transistors properly? (with all the specified hardware in all the specified places?)
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After installing a new speed ball properly my 5 watt resistor smoked and the ceramic housing disintegrated. Also I am only getting about 13 Volts from Terminal 1 and about 40 from terminal 2 :(
I'm sorry, but I would imagine that it was not installed properly. Please re-read the last note on Page 42 of the manual. "If you see smoke, SHUT IT OFF!!!"
Post some pictures of the Speedball installation. The forum will get you sorted in no time. :)
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Thank you all for your near immediate responses. I will re-recheck my speedball install as the gentleman from Japan suggests and post pictures if the solution still eludes me...
Thank you wonderful men again.
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Please double and triple check your work. I have a perfectly working crack with speedball. Aside from a bad solder joint in my initial build, the only time I ever had an issue is when I did a mod and mis-wired one lead. My point is if the instructions are followed precisely, your crack will work well, baring a defective component.
BTW it took me a while to recognize that one wire was not properly connected
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I am still unable to resolve my issue... Perhaps pictures of my Speedball install will assist you to assist me?
Thank you for your time in advance.
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Pictures always help
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Trim those TIP50 leads. They might be shorting on something. Same goes for the 2N222A leads. Anything sticking out more than 1/8" or so, give it a trim. Be careful to remove all loose clippings too.
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Try running the amp with no 6080 installed and let us know what the voltages are on terminals 1-5.
-PB
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I ran the amp without the 6080 tube and recorded the readings:
Terminal # 1 - 81.5 bolts
Terminal # 2 - Erratic Readings
Terminal # 3 - 0
Terminal # 4 - 0
Terminal # 5 - 80 bolts
Also, thank you man from Japan but it appears there are no shorts here to report...
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fs9.postimg.org%2F6ex1z96e7%2FIMG_3590.jpg&hash=29f69cf7183a45c9184725c33ad703223892c4ae)
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I ran the amp without the 6080 tube and recorded the readings:
Terminal # 1 - 81.5 bolts
Terminal # 2 - Erratic Readings
Terminal # 3 - 0
Terminal # 4 - 0
Terminal # 5 - 80 bolts
You can't have ~80V at 1 and 5 without having more voltage at 2 and 4. It's possible that you need to go up one scale on your meter to see what's there.
This basically confirms an issue with the large board feeding the 6080. Nearly every time we see this, it's because the hardware used to mount the TIP50 has not been installed properly, and the metal tab of the TIP50 is touching the heatsink through the mounting screw.
-PB
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Perhaps you can check that you have the right part attached to the heatsink.
The part number that shows partly on your picture reads MJE57...
I enlarged a detail of one of your photos. Maybe it is not the TIP-50 transistor you are supposed to have there.
Richard
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Now that's impressive, how on earth did you spot that!
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Well done, Rich. This is a classic example of why we suggest builders who are having problems have someone else look over their work. That person doesn't even necessarily need to electronics knowledge though, as shown here, experienced eyes here can often spot things quickly. A fresh pair of eyes will often spot a discrepancy that we as builders can look at again and again without seeing.
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I "went up one step up on [my] meter" as Caucasian Blackplate suggested which corrected my previous error. The true readings are:
Terminal # 1 - 84 volts
Terminal # 2 - 221 volts
Terminal # 3 - 0
Terminal # 4 - 221 volts
Terminal # 5 - 81 volts
You gentleman are indeed astute for noticing the transistor discrepancy... My replacement speedball came directly from Bottlehead with the alternate transistors... It is the model MJE5731G in place for the TIP 50...
I have attached both datasheets and as far as I can tell it should be equivalent... Should I try replacing the replacement with the original version of the transistor?
Thanks again for your assistance.
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One is a PNP, and the other is an NPN style transistor. I assume you received those in error so you need to switch back to the TIP50's.
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Sorry about the mixup. We can send out the correct TIP50s. If you can contact us with your real name (can't send stuff to usernames) we will get those out promptly.
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Headed to RadioShock now for more solder and possibly a rocker switch (which Joshua overlooked sending me last month on the 18th when I was shipped this incomplete speedball kit)... I plan on using the TIP's from my botched speedball which I had removed. I just want to groove as quick as I can.
What I'd like to know is if Queen Irene can get a percentage off on one of those fancy shmancy tubes I've been receiving all these emails about...
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Headed to RadioShock now for more solder and possibly a rocker switch (which Joshua overlooked sending me last month on the 18th when I was shipped this incomplete speedball kit)... I plan on using the TIP's from my botched speedball which I had removed. I just want to groove as quick as I can.
Please let us know who you are so we can send these items to you.
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The most recent readings:
1- 90
2-194
3- 0
4-193
5- 86
6- 0
7- 0 (followed it back to B3 and there is no voltage at the tube either)
8- 0
9- 130
10-0
11- 0
12-0
13- 195
14- 0
15- 208
20- 0
21- 223
Although it no longer emits glow, perhaps another 5 watt 270 ohm resistor would go well in place of my original...
My most recent Invoice ID: 1163
The one prior was: 1085
My sincerest thanks
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Still not Crackin' :'(
I only hear faint music from the right channel when everything is cranked...
Terminal 7 from the tube is not an issue?
Thanks
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fs23.postimg.org%2F607p1n1kr%2FIMG_3607.jpg&hash=150fbd27b107483a98d66a41510d5e3664158924)
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Terminal 7 from the tube is not an issue?
If your voltages are not correct, it should not be a surprise that the amplifier isn't working. You also shouldn't attempt to use it since the voltages are not correct.
Neither half of your 6080 is functioning properly, the voltage at terminal 9 is also an issue.
Were you able to source TIP50 transistors?
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One of my hookups broke and was overlooked... But now that's fixed. The particular wire is the one in the pic...
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fs22.postimg.org%2Fwy8m4bcg1%2FIMG_3613.jpg&hash=dcefb4cad58d2a65afc3d195519fb31bc37dfbab)
So the numbers below indicate what my latest measurements show.
1- 93
2-174
3- 0
4-173
5- 72
6- 0
7- 0 (followed it back to B3 and there is no voltage at the tube either)
8- 0
9- 96
10-0
11- 0
12-0
13- 168
14- 0
15- 189
20- 0
21- 214
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Not to state the obvious but there's lots of wires in the photo you posted
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The one in the middle coming down from the big SB board............
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Not to state the obvious but there's lots of wires in the photo you posted
The undone red one...
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Would it be wise to revert back to the lack of a speed ball in order to assert that the stock crack is in fact intact?
Not knowing what to do a few weeks ago I went and redid all of my solder joints anew... I doubt I mucked that up like a fool but it would be nice to rule that possibility out.
So (Again) the numbers below indicate what my latest measurements show.
1- 93
2-174
3- 0
4-173
5- 72
6- 0
7- 0 (followed it back to B3 and there is no voltage at the tube either)
8- 0
9- 96
10-0
11- 0
12-0
13- 168
14- 0
15- 189
20- 0
21- 214
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Can you post some photos of the top and bottom of your larger Speedball board?
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Numbers from the latest tests since I removed all Speedball components:
Resistance check:
Center pin on left channel reads "0" ohms not 90 Kohms... same "0" reading at the spot where it connects to the pot.
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fs2.postimg.org%2Flf04yufyh%2FIMG_3809.jpg&hash=07de5e84cbd34766628a314e3fecb40efb59a14f)
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Center pin on left channel reads "0" ohms not 90 Kohms... same "0" reading at the spot where it connects to the pot.
Are you getting normal readings otherwise? Can you post a photo with all the meter in it (just to be sure).
-PB
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Usually this indicates bridging the hot to ground on the input jack. It looks like there is a lot of solder on the center pin of that jack, so it could be extending across the plastic insulation. Check carefully and remove solder if possible.
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Usually this indicates bridging the hot to ground on the input jack. It looks like there is a lot of solder on the center pin of that jack, so it could be extending across the plastic insulation. Check carefully and remove solder if possible.
You were correct Sir. One RCA jack was shorted on my crack exactly where you indicated. Now it's fixed and it sounds great. When I get a chance I will attempt a reinstall of the Speedball.
Before I move on to that however, whenever I turn the volume pot, up or down, I get a lot of these scratching sounds through my Sennheiser HD650's...
Please advise me guys. You've proven able to correctly detect the particulars which I continually neglect, and I'm moved.
It'd be nice to get one more round of your sound advice.
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Do also consider the possibility that a solder joint on the pot may be marginal, and sensitive to the minor mechanical stress of adjusting. I agree with Grainger that a bit of dirt inside the pot is the likeliest cause, but re-flowing a half dozen solder joints is much easier, unless you already have the De-Oxit or other contact cleaner on hand.