Build Log: A Physician hooked on Crack (My very first DIY project)

[Laudanum]

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."

 

[Grainger49]

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? 

 

[sanadsaad]

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.

 

[Grainger49]

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.

 

[Laudanum]

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.

 

[Grainger49]

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.

 

[Doc B]

If you are using a 240V transformer with 240V mains the voltages will be the same as using a 120V transformer with 120V mains.

 

[sanadsaad]

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.

 

[Grainger49]

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.

 

[Paul Joppa]

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.

 

[Grainger49]

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.

 

[sanadsaad]

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)

 

[Grainger49]

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. 

 

[sanadsaad]

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 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

 

[sanadsaad]

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!

 

[Noskipallwd]

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

 

[Laudanum]

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.

 

[Grainger49]

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.

 

[earwaxxer]

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!".

 

[jimiclow]

Congrats!
Follow Grainger's advice, get a Fluke meter. It's the Welch Allen of meters.