Bottlehead Forum
Bottlehead Kits => Crack => Topic started by: sanadsaad on August 14, 2012, 12:14:34 AM
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Ok so im starting the build finally. Got a hold of everything to assist in the build after consulting with you guys. Went through the manual a couple of times. Now here's my 1st question. I have bought the Speedball upgrade with the Crack. Should I first build Crack and then upgrade to speedball or would it be better and easier to skip some steps on Crack to put the Speedball upgrade in one build? Plan is to go through a few soldering videos(paceworldwide, other DIYers videos), practice a bit and then start with the Crack. I picked up the Minty boost recharging device and will use it as my first soldering project(I have never soldered before in my life). Tonight i'll assemble the parts as shown in the manual. Im really bad with the screw sizes mentioned in the manual. Placed them side by side and used the parts list to get a good idea of which is which. I will be needing tons of help when I start soldering and then testing voltages. Going through the build threads here has made me a bit scared regarding voltages and damaging my Senns(650). My predicament is that Im in Oman and there arent many components available here. If I blow something up, project ends there. So i'll go step by step and keep this thread updated. Wish me luck!
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Hello,
The Bottlehead folks all recommend building the Crack without the speedball first, this is what I did. This will give you an idea of what speedball does for the sound. This gave me an appreciation of the importance of a constant current source. Also, you make the build just a little longer. I was extremely satisfied when I finished, but I also was disappointed that I had nothing left to build, so much so that I ordered the Eros!
Cheers,
Shawn
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With no source for parts handy just measure the resistance of each resistor before soldering. There are not many in Crack, but it will help.
After each solder joint measure from a permanent part to the lead. Say you soldered a resistor to a terminal. Measure the resistance from the terminal to the resistor lead. Do not include the solder joint. This will help you find any solder joints that might be iffy.
For your meter readings check question 7 in the FAQ Thread (http://bottlehead.com/smf/index.php/topic,2408.0.html).
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If you need reference in identifying screws and other fasteners these might help. http://www.boltdepot.com/Fastener-Information/Printable-Tools/ Just make sure you print to scale. Also, after thinking about it, I would definitely build the Crack stock first. That way if you have to troubleshoot you don't have the speedball to worry about. Also, when you install the speedball you wil have a properly operating amp, which makes troubleshooting the speedball much easier.
Cheers,
Shawn
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So I finished the assembly of the board and before I start the wiring, I thought i'd do my first soldering on a smaller project: The Minty Boost kit charger for USB devices. Turns out im not that bad when it comes to soldering but Im really glad I tried on this PCB first. Much of what I read, saw and thought regarding soldering was a bit different from actual hands-on soldering. Although I thought a couple of solder joints looked weird, and some of the solder didnt fill through the hole, the voltage testing went perfectly and The Minty boost worked like a charm. So I think im ready for wiring now. Lets hope the terminal soldering goes well. One question: I saw videos of people tinning the wires before soldering to the terminals. Should I do that?
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I agree with Tim, you shouldn't need to tin wires.
Good luck!
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It says in the manual to go one turn around the safety ground lug. I inserted the wire into the safety ground lug, turned right and kept the wire at the 16L to be soldered. Am I doing it correctly or do I need to do another loop full around the lug?
Another query: When I connect the red and black wires to B8L/B8U and B7L/BLU respectively, do I solder them as one? Does it matter if solder connects both above and below wires in their respective holes in the heater pin?
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If the manual suggests a full wrap of the ground lug, it's to make sure there is good physical contact of the wire to the lug before soldering. The same reason why it's suggested to crimp the wires with needle nose pliers to the terminals they will be connected to. In all actuality, if you have already soldered but made good physical contact with the lug without wrapping, it will be fine.
The upper and lower holes of the large tube socket lugs are electically the same. If I understand what you are asking ... no, you dont have to completely bridge the solder between the lower and upper holes. The lug itself is a conductor for it's entire length. Doesnt matter if the solder brigdes both holes together or not. Just make good contact with the wire to the lugs and then a good solder connection.
Same will apply to the terminal strips upper and lower connections. Just for an example, T-17U and T17L. They are electrically the same, connected by the fact that the terminal tab itself is a conductor. So when a connection is called for both the upper and lower portion of the same terminal number, you dont have to make a solder bridge between the two holes.
Hope that was what you were asking anyway ;)
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Welcome to the first of many equally fruitful addictions!
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Yep thanks a lot Laudanum! Man am I addicted. I started soldering hours back and thought "Hey, id start and do two pages and do some more tomorrow." Im left with just 8 pages(an hour max) and im done soldering and onto voltages! Its 5am in the morning. Time just flew by! Im glad I ordered the speedball upgrade with this. More time spent building! Im as high as a kite right now. Part of it might be attributed to the solder fumes ive inhaled :)
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Crack will do that to ya................ ;)
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I bought one of the solder fume filter fans some time ago, and it never gets used. Waste of money.
Cheers,
Shawn
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Completed soldering. Im seeing a mismatch on the resistance readings. Bad joints probably. Here they are:
Terminal:My reading:Manual reading
1: 22.6: *
5: 22.6: *
7: 0: 2.9
9: 0: 2.9
13: 0.5: * to 270
B3: 0: 2.9
B6: 0: 2.9
RCA
Center: 101.3/101.5: 90K-100K ohms
HELP!!
I think 7 and 9 are cold joints. Im workin on those. I know its probably something basic but im an absolute beginner so im posting my results here as I go along!
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Pulling out my "custom" schematic with terminal numbers on it...
I have now figured out you haven't been using multipliers. They are important.
As above for the meter readings and making heads & tails of them refer to the link supplied.
Terminal 1 is the plate of the 12AU7 so with no tube there it is connected to the power supply through the 22k1 resistor. The capacitors should charge giving a reading that starts in the thousands of ohms and goes up to maximum (that is when the batteries in the meter charge the caps enough to be infinite resistance).
22.6 ohms, not 22.6k ohms says something is wrong. Check the resistance of the resistor between T4U and T5U, but measure from tube pin 1 and T4. Check the resistance of the resistor between T2U and T1U but measure between tube pin 6 and T2. Both should be 22k1 ohms.
Check the 270k ohm resistor between T13U and T12U (page 30, bottom of the page). Since it is across capacitors it will start at the value of 270k and climb.
Terminals 7 and 9 are attached to the left and right cathode resistors of the 6080 tube terminal B3 and B6. Those are the big honkers in the middle of the chassis. It is unlikely they were shorted (zero ohms that you read) to begin with. Each should measure about 3k ohms. Try placing your meter leads on the resistor leads of the left one then the right one. You should get close to 3k ohms for each. If you get zero, there is a short somewhere that is shorting out the resistors. I suspect the resistors are good.
Terminal 13 is the output of the high voltage power supply. It should charge all three big capacitors. It should start at about 270k ohms and climb to infinity or near that. If it is shorted there is a big problem.
Start looking for this by carefully checking the orientation of the power supply diodes, manual page 27, lots of pictures. Verify that the banded ends of the diodes are as shown in the picture.
Next verify that the capacitors have the white banded end where they should. They are all installed on page 30. The first one has the white band toward the front of the amp, it is pictured from the side. The second and third (mounted horizontally) also have the white band toward the front.
Your RCA jacks are within 1.5% of expected. That is as good as it gets.
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I did the checks as you asked. Here are the findings:
Tube pin 1 and T4 = 22k ohms
Tube pin 6 and T2 = 1
Terminals 7 and 9, both measurements are 3k ohms.
Terminal 13 is still giving me 0.5k ohms reading. Ive checked and rechecked all orientations and they are according to the manual.
Im trying to upload images onto photobucket and will post any images of specific terminals you may want to see. Im attaching a pic of terminal 13.
EDIT: If it makes any difference, on page 19 of the manual, there's a revision advising attaching a black wire to terminal 4 and soldering to terminal 14U instead of 22 yielding a quieter operation. I soldered to 14U. If that helps in anyway.
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Ok, your picture verifies two caps and the existence of the 270k ohm resistor.
Terminals B3, B6, 7 and 9 are good.
One plate resistor is clearly soldered well but the other one looks to be one ohm.
I am wondering about the grounds throughout the circuit. What point are you using to measure your resistances to? That is, the meter lead you do not move.
Here is the ground circuit from another thread:
The start of the grounding points is terminal 3. This jumps to the 2 left lugs of the volume pot and to the back of the chassis from there to the RCA jacks. From the top left lug of the volume pot there is a grounding jumper to the two bottom lugs of the headphone jack. This jack may be different than what is being delivered today.
Also from terminal 3 you go to the center lug of the 9 pin tube socket. This is the ground route for the LEDs in the cathode circuits of the 12AU7s.
The power supply ground comes from those bottom headphone jack terminals to terminal 12. From there it jumpers to terminal 14 and ends at terminal 20.
The heater (AC) supply is a ground wire from transformer terminal 4 to terminal 22.
Ok, so all this means you should clip on to the chassis (which is screwed to terminal 3 the source of all the grounds). Tracing from the plate outward you should read zero to T3, Volume 2 left lugs, both RCA outer conductors, headphone jack bottom terminals, T12, T14, T20, center pin of the 9 pin socket, and to T22.
Other grounds that should be solid are pin 8 of the large tube, pin 4 and 5 of the small tube, T8, T11, T14, T16, T17, T20, T21 & T22.
So, clip one meter lead onto the top plate. Then trace the circuit with your other meter lead starting with terminal 3. You should read zero or what you have determined as zero for your meter at all points. A fraction of an ohm is good.
Finally a couple of questions, do you have an analog meter or digital? Does it autorange?
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Alright so I did a full recheck and turns out the leads in terminal 3 were inserted but not soldered. Mustve been missed during the early hours. Soldering those and reheating the 7 and 9 terminals which I suspected were bad, here's the final resistance checks that now differ from the manual:
Terminal 1: 22.6k/*
Terminal 2: 0.5k/*
Terminal 4: 0.5k/*
Terminal 5: 22.6k/*
Terminal 13: 0.5k and does not climb/* slowly climbing to 270k
I was using terminal 12 and readings are the same when I test from the chassis plate. And my multimeter is a digital one. Here's the link:
http://www.uni-trend.com/ut33c.html
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1, 2, 4, 5 and 13 are listed with an * because, from the manual ... "The values signified with a * are going to vary from ohmmeter to ohmmeter because these terminals are connected to the filter capacitors, which try to charge themselves off the battery in the meter, causing a fluctuating reading. If the circuit is connected properly these readings will wander in the tens or hundreds of Kohms or higher range. What you want to watch out for is a zero reading at one of these terminals, which would indicate that something is mis-wired."
You may very well be ok but Grainger or one of the more tech savvy will chime in to confirm or assist further.
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Desmond the readings look fine to me except for the terminal 13 reading not rising. If the experts say it's fine, i'm raring to go onto the voltage testing! I just realized I havent been given the fuse or the IEC power cord with my kit. Oh well. Might as well run to the store now while I wait for the go ahead. It's a 5A fuse right? Thats what it says on the parts list. I have a 10A fuse sittin on my desk but I guess that wouldnt do.
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Doc suggested a 1 amp slo-blo in another thread. Mine shipped with a 1 amp as well. I think there were too many fuses nuisance blowing with the .5 amp but was never changed in the manual. Go with a 1 amp. I believe it is a 20mm fuse.
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Looking at your meter it is a digital that needs the scale selected, not autoranging.
Whether the reading rises might be a function of your meter. First try directly across one of the capacitors. The reading typically rises across a capacitor. A good one to try is the first one across terminals 20 and 21. This is a good one to test for a rising resistance. Then swap the leads the resistance should show a negative value dropping.
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Just noticed that you've typed 5 amp fuse. You may have edited your post while I was typing my response yesterday or I may have just misread. Reagrdless, the manual states a .5 amp (0.5, 1/2 amp fuse) NOT 5 amp. Atleast my manual does. Again, Doc B recommended a 1 amp slo-blow fuse in a post on this board. But dont use a 5 or 10 amp. Make sure it's .5 or 1 amp fuse ... preferably 1 amp slo-blow.
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Ok, going back to the start of the resistance checkouts:
Terminals 7 and 9 (B3 & B6) are no longer zero ohms to ground, right? The solder joint should have fixed it.
Your last readings indicate that terminal 13 is 500 ohms to ground, which you read. So terminals 1 and 5 wired back to terminal 13 through the 22k1 plate resistors check all the way to terminal 13 (22k1 +500= 22k6). Let's say that the lack of a climbing resistance reading is a function of you meter. At this point every reading you have that is not right is a "climbing" reading.
It may be the time for the smoke test (stock fuse if you don't have a 1 amp slow blow). I know you don't have spare parts available close to where you are, but at some point you are going to have to turn the Crack on. Cross your fingers and turn it on and off very quickly, as fast as you can. Trust me this has a function.
Then turn it on with it upside down (best to have it on and plug it in), have one of your meter leads clipped so you can start taking voltage readings.
Pray for no smoke. Post back.
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Tried the terminal 20 and 21 resistance check. Reading is 0. Tried to start the crack twice with a 1A regular fuse(cant find slo-blo in the market). Blew up twice. I found the following replacements in the market:
-the uf4007s
-270 ohm 5W wirewound resistors
-3K ohm 10W wirewound resistors
--All the electrolytic caps
Cant find the metal film resistors anywhere though.
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Are you saying that the whole power supply blew up?
Everything you list will work just like the original. The 10W resistors will be larger than the ones you have, believe it or not. How did you determine that those needed replacing. They are not in the power supply. Maybe they got tied to the power supply somehow?
We have to solve the problem with the power supply first. There was a short in the high voltage to take all this out.
I don't know if you need film resistors yet.
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Oh no no. The fuse blew up. I went to a shop to get the fuse and checked if they have any replacement parts in case they blow up later. The shops here close for 8 days on account of Eid so I wouldnt be able to get anything if I needed em. So lets start the troubleshooting. Im going over all the wires again according to the manual to see if I missed anything.
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While you are checking things, make sure of the orientation of the diodes and capacitors. This is fairly often the cause of blown fuses. Check the orientation of the sockets as well - the octal has a slot for the pin on the tube bass, and the sockets have been known to get installed 180 degrees out. Finally, make sure wires go to the correct terminal - that's another common mistake, and especially hard to see after you make the initial mistake.
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Tried the terminal 20 and 21 resistance check. Reading is 0. . . .
This is wrong, the capacitor should be a high resistance to ground, terminal 20. Does terminal 20 read near zero resistance to the top plate? If the capacitor is internally shorted you get zero ohms and the fuse blows. But I don't think this is the problem because you got a zero reading before applying the power. A bad capacitor often, not always, has a domed end. Ends of these power supply caps should be flat. If not, they are bad.
But my next suggestion is a little harder. Remove one cap from the power supply and measure it. Regardless of whose meter it is you should get a high reading not a low reading.
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The caps are all flat. One thing I should mention again. There was a revision in my manual advising me to connect a black wire from terminal 4 to terminal 14U instead of 22U. Im desoldering the terminal 20-21 cap right now. will post soon as tht's done.
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That revision to connect from transformer terminal 4 to 14U instead of 22L is a possible solution for quieter operation of the amp. It isnt your problem unless ... the solder joints are bad.
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Cap removed from 21/22. Reading climbs from 0 to infinity. Cap still off. didnt resolder it. Without the cap, the resistance b/w ground and terminal 13 climbs from 0 to infinity as well.
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Aaaaaaaahahahaha(crazy laugh when one gets something right)!
It was the capacitor at 20/21.
New resistance readings:
Terminal 1,2,4,5 and 13: 0 climbing to infinity
Terminal 20 and 21: 0 climbing to infinity now when previously it was giving zero.
Turns out the cap terminals werent soldered properly. Actually they were soldered well but I desoldered, tested the cap as suggested by Grainger and then tightened the mechanical connection of cap, wire and terminal and then tested resistance. Then I soldered and rechecked. Onto the third fuse then?
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This is odd. I left for a coffee break, came back and re-did the resistance check and now im back to the same old readings I was getting before.
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Its definitely a soldering issue. I find that if I remove a little solder from the joint with a wick, I get proper resistance numbers. Finally fixed it and did the voltage checks. Theyre all perfect! As it's 240VAC here in Oman, my voltage numbers are more or less double what's in the chart. The only question is regarding A9. It should be 0 but im getting 5V. Other than that, the voltage numbers are perfect! I could smell something when I was voltage testing but it was probably the tubes heating up. There was absolutely no smoke and the fuse didnt blow. Thanks guys! You're awesome. Big thanks to you Grainger for pointing the 20/21 thing out. This is one hell of a forum! Ok, now should I solder the black wire to the headphone terminals and ground em to fix the headphone issue or should I leave it at that? Cant wait to connect it to source. Another question. I have a lot of HD tracks on my laptop. Can I burn em to ordinary discs? Never done that. Anyone who has, I'd appreciate the help.
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I have a schematic marked with terminal numbers. According to that schematic nothing should be connected to T14 except the cap and two resistors. The power to the 12AU7 plate should come from T13 to T4.
T22 is a ground, T4 is connected to a plate load resistor. They shouldn't be connected, ever. I don't see a black wire from T4 to anything in the manual I have.
The only thing I find in the manual using the search function for Terminal 4 is a red jumper to Terminal 2.
I will look further in the morning.
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The headphone terminal votage shoots to 31 for less than a second on startup then its all zero from there. Should I ground it as advised or start listening without that? I read Dave's thread where he damaged his headphones and wanted to avoid it.
Also, everywhere in the voltage checking, it's said not to touch the live amplifier with both hands. After fitting it in the wooden board and puttin it on my desktop connected to the CD player, can the top plate be touched or would it conduct current?
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Hello again, this is a great forum isn't it, great to have guys like Grainger and Desmond sharing their knowledge and experience. As long as you don't plug your phones in until you turn the amp on you should be safe, I used mine that way for some time. The top plate does not carry current, so you are fine. If you use two hands when measuring voltage you make a nice circuit between your hands, if you happen to receive a shock it would travel right across your heart. Electrical current takes the path of least resistance. The amp is safe during operation, just don't reach under it when it is on, and when you take it from the base for any reason turn it off and let it sit a few minutes. Hope this helps.
Cheers,
Shawn
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... As it's 240VAC here in Oman, my voltage numbers are more or less double what's in the chart....
If true, that's very bad. There is a version of the power transformer designed for 240v input; all the circuit voltages will then be the same. If you have the 120v transformer, don't put 240v on it. The circuit is designed for +/-10% variations, but can't handle 100% variation!
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Thanks Shawn! Yea I think i'll get the headphone grounding done while I have all the equipment out on the dining table(makeshift workplace).
Paul, it's a 240V transformer! I mentioned it to Doc when I placed the order. And if the readings are for 119VAC as mentioned in the manual, shouldnt the ones for 240 be more or less double?
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As it's 240VAC here in Oman, my voltage numbers are more or less double what's in the chart.
I completely missed the double part in your post, the circuit voltage readings should be the same, as Paul said. The 240v and the 120v transformer will produce nearly identical voltage and current readings on their respective output taps. I would verify what transformer you received before putting power to it again. I am not sure how to do that. I think you use resistance readings, I am sure Paul, Grainger, or Desmond will let you know what you need to do.
Cheers,
Shawn
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Not tech savvy enough to help with the transformer and voltage, sorry.
To Grainger ... The reference was to the connection between terminal 4 of the transformer, not a terminal strip. It was originally instructed to take the wire from transformer terminal 4 to 22 but a revision suggested that taking it to 14 may result in more quiet operation. It's a ground.
Per manual:
"Cut a 2" (50mm) piece of black wire, strip both ends back 1/4" (6mm). Attach and solder one end to power transformer terminal 4. Attach and solder the other end to terminal 22L."
"REVISION 5/6/10:
Making this wire 3" long and connecting it to Terminal 14U instead of terminal 22L may yield more quiet operation."
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Desmond,
Thanks, that makes sense this morning. Somehow I had missed his two posts above my last one.
I'm with everyone else, double voltages are bad. That will make the capacitors blow up, literally. This worries me.
Does your transformer label say 240V or 120V? Transformer terminal 1 is 0 Volts, what does your transformer terminal 2 say?
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Ok now im concerned. When I read "The following voltages have been made with an AC mains voltage of 119VAC" in the manual, I thought that implied that 240VAC would be different.
Grainger, Terminal 1 is 0, 2 is 1. The transformer is for 240V. Says so on the sticker.
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I'm wondering if the transformer was somehow mislabeled.
Dan or Paul might have some insight on whether there is a physical difference in the two transformers. Maybe a resistance measurement of the primary winding will tell if it is indeed 240V or a mislabeled 120V.
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Not for the OP but for those who may be able to help ... If the secondary is 6.3 volts for both 120V and 240 volt versions of the transformer, then wouldnt the turns ratio be different for each? Double for the 240 volt transformer compared to the 120 volt? (or is it half?). But I suppose you would have to know the number of turns anyway, to be able to work out the math ...
If it does turn out to be a mislabeled transformer, couldnt an inexpensive step down could be used while waiting on a 240 volt transformer? Im jumping the gun here, I know, but maybe some preemptive food for thought.
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Desmond's post made me think of the earlier post. If the heater voltage was doubled the heater would glow brightly for a second and burn out. So there is some hope that the transformer is 240V. The heaters were reported as glowing. That would have been very brief if the voltage was doubled, at least it was when I did the same thing.
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If you are using a 240V transformer with 240V mains the voltages will be the same as using a 120V transformer with 120V mains.
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Im going to start off with something simple, since my technical know-how is very low regarding electrical circuits which is why I chose this DIY kit to learn more. I think my multimeter is shady. I'll go borrow one from a nearby electrician. His equipment would be better than my beginner stuff. I'll post back in a bit.
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If your electrician friend has a Variac you can use that to bring the amplifier on slowly. If he has one and you can borrow it, post back. If he has a step down transformer as Desmond suggests, borrow that and post back.
With either you can make a quick check to see whether the transformer is doubling voltage or not.
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As Grainger says, measure the DC resistance of the primary winding, which is the one that the power goes to, transformer terminals 1 and 2.
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With the resistance from Transformer 1 to 2 PJ can tell you whether it is a good 240V transformer or a 120V transformer mislabeled. The last one would cause double voltages everywhere.
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Hey! M back. All voltages are perfect. It was the multimeter giving errant readings. Did a check with his old Japanese analog multimeter as well as a digital one. So it all points towards my cheap multimeter! I'll be investing in a good one if I am to continue on this DIY path. Here are the readings I jotted down:
Terminal My reading (manual)
1 76(90)
2 152(170)
3 0(0)
4 170(152)
5 73(90)
6 0(0)
7 97(100)
8 0(0)
9 94(100)
10 0(0)
11 0(0)
12 0(0)
13 153(170)
14 0(0)
15 172(185)
20 0(0)
21 191(206)
A1 73(90)
A2 0(0)
A3 2(1.5)
A4 0(0)
A5 0(0)
A6 75(90)
A7 0(0)
A8 2(1.5)
A9 0(0)
B1 76(90)
B2 153(170)
B3 97(100)
B4 73(90)
B5 154(170)
B6 90(100)
B7 0(0)
B8 0(0)
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sanadsaad,
We really need a name here. Glad to hear that you got it all straightened out.
My classic suggestion is to buy a nice Fluke digital meter and you will never need or want another meter for life. They can be had for under $100, often about $80.
Once you fall in love with the Crack you will be back. Imagine what tubes do for a pair of speakers.
Again, congratulations.
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Thanks a lot Grainger, Desmond, Paul, Shawn and the awesome community here! I had never soldered/built any electronic component in my life(although I was fascinated by them since I was a kid), and I still managed to build it! If it wasnt for you guys, I wouldnt have been able to troubleshoot at all. Oh and Grainger, I still have Speedball left :D Next upgrade definitely will be some nice speakers and a Tube amp to go with it! For now, time to enjoy the sweet sweet pairing of a Crack and Senn HD650! My name's Sanad by the way. Sanad Saad. Its an Arabic name meaning "Strong Support". I should be calling you guys Sanad :)
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Just finished a few 3 hour long listening sessions. Are you guys seriously planning to tell me it gets better than THIS when I upgrade to Speedball? Now I know what everyone means when they sing praises of Tube amplifiers and particularly the Crack. I cant stop playing every song in my library and I have thousands which I am listening and rediscovering. Just WOW. Kudos to you Doc B for one hell of a kit.
PS: I told my dad(a big audiophile while I was growin up) to come and test out this amp with his classical music CDs and now he wont get off the recliner I had set up beside the amp!
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Sanad,
Glad to hear you have got the Crack making music, I have the HD650s as well and they really are great together.
PS: I told my dad(a big audiophile while I was growin up) to come and test out this amp with his classical music CDs and now he wont get off the recliner I had set up beside the amp!
Now you will have to build one for your father. Enjoy!
Cheers,
Shawn
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Sanad, Im not nearly as tech-smart as a lot of these gents but happy to help where I can. More importantly, great to read that she's up and running. Hope you really enjoy it ... and you will. Speedball is a definite upgrade. It probably wont make for the thrill that you had when you first got Crack making music but you will notice the change for the better. Enjoy it as it is now, in stock form, for a little while. Familiarize yourself with the sonics and then do the speedball installation and enjoy the changes and improvement that it brings all over again. Shortly after that you'll be looking into the film capacitor upgrade ;D Modifications can be just as addicting. Maybe not having as easy access to parts is a blessing in disguise ;)
Congrats and enjoy.
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Things will settle in as the circuit, mostly the capacitors, break in. Things will get better during this period. Once it settles out after a hundred hours of listening or a few hundred as you are really familiar with the sound with your old favorites, then drop in the Speedball.
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Sanad - cool to hear you are 'diggin' your gear! Most people dont understand our passion. The cool thing is, there is no end to the pursuit! When they lower me in the ground I will be like - 'wait!... just this one last tweak!".
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Congrats!
Follow Grainger's advice, get a Fluke meter. It's the Welch Allen of meters.
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After enjoying countless hours of sweet music on Crack, I noticed static in both channels that does two things:
1. Increases when I disconnect source which is my laptop connected via 3.5mm to RCA
2. Increases/decreases when I turn the volume up/down respectively.
I thought I'd post it here rather than start a separate post. Any ideas?
EDIT: It is very faint when I connect RCA to my Mac. It goes away when I play music.
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It could be the source.
Either make a pair of shorting plugs with some cheap RCA plugs and a pair of resistors, 10k ohms is good, or use a pair of alligator clip jumpers to short the center conductor of each RCA input jack to the ground. That is a jumper for each channel, center to ground.
If the computer is close to the Crack it can cause all sorts of noise. Same for a cell phone.
The above will vindicate the computer.
Also, reseat both tubes multiple times to clean them (I may have suggested this earlier in the previous 4 pages, still a good idea).
If you have a spare set of tubes, always a great trouble shooting technique and way too much fun rolling different tubes, you can eliminate the tubes as the source of static.
BTW, new tubes need to "form." If you have put in 100 hours on the tubes, they are formed. If not keep at it, you don't have to listen.
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Just finished installing the speedball. All voltages perfect! I was wondering that while I have the "patient" open and on the table, I was thinking if I should ground the headphone jack. The two unused terminals I connected but which terminal should I connect it to to ground?
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Sanad,
Excellent! I'm glad to hear that everything was good as soon as you converted. Here we hear of the problems more than the successes.
I think there is a sticky in the Crack folder concerning a tweak to improve S/N ratio. I think this is what you want to check out.
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I dont think it specifies where to ground. Or, I should say, the best point to ground, if there is such a point. I havent done it yet myself so I have no specifics to add.