[fishski13]

looks awesome Jake!  is that the black painted finish Par-Metal offers, or did you paint it?

 

[jdkJake]

Thanks for the kind words guys!
 
Quote:

nicely done Jk..looks like we both had the same idea with regards to the windows..

 
Now you only need to transition over to orthos to make the journey complete lol

That's cool. I look forward to seeing your take on the concept. You know what they say about great minds... 

 
Quote:

That's a three inch high ParMetal isn't it? How is the heat? I was going to go the same way bit am worried about heat buildup in the case.

Yes, it is the three inch high case. I have not run it long enough to get a good idea on the heat build up, but, I will for sure find out. I used quarter inch standoffs, so, there is plenty of space from the top of the heatsinks to the top of the case. I also drilled two extra strips of ventilation holes in the center of the case. My goal was to not only help vent the heat from the e12's (which get surprisingly hot) but also the inside MOSFET's and Rail PS sinks. I will try to get some thermal readings soonest. BTW, I tried a "free-style" technique on those holes using the laser on my drill press. Let's just say a punch technique for started holes is far more accurate. Good thing it is on the bottom and out of sight.
 
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The engravings on the windows look great! Congrats on casing it up! Actually, what are you using to side mount the e12s?

 
Thanks. I can only claim partial credit for the engravings. The design is mine, but, I used lasercut to do the actual engraving. 
 
The e12's have an asymetrical hole pattern for standoffs, so, only two of the standoff holes will allow back-to-back mounting of the two boards. The aluminum standoffs I had on hand were too big in diameter such that they touched some traces/solder joints, so I went with these from RatShack:
 
   http://www.radioshack.com/product/index.jsp?productId=2102860
 
Still had to trim them to fit flush, but, no chance of shorting anything. To secure to the bottom of the case, I went primitive and used two holes to the side of each standoff and a pair of black nylon tie-wraps. Not as good as a screw mount, but, it is also not going anywhere.

 
Quote:

looks awesome Jake!  is that the black painted finish Par-Metal offers, or did you paint it?

I painted it. I went with the black anodized case hoping it would look good enough as unpainted would dissipate heat the best, but, once I saw it, I knew it needed a paint job to look even remotely professional. So, my fav, Black Satin Krylon makes yet another appearance. I should buy stock in that company.
 
Parting pic for the evening...
 

 

[BK_856er]

jk, that parting pic is outstanding.
 
Got my boards from glassjar today - living in the same town has its benefits.  Boards look great.
 
Ordered all Panasonic FM (and one FC) electrolytic caps and also the other bits mouser couldn't cover.
 
Put an inquiry into SumR for the RC0050 051 8.
 
Getting closer....
 
BK

 

[jdkJake]

Thanks. Be sure to read back into the thread a bit regarding the transformer. You might want to dial it back a bit, but, you would be breaking new ground, so, be sure to understand the change and why you you would be making it (if you indeed make a change).

Glad to hear your part hunting went well.

 

[BK_856er]

 
Quote:

Thanks. Be sure to read back into the thread a bit regarding the transformer. You might want to dial it back a bit, but, you would be breaking new ground, so, be sure to understand the change and why you you would be making it (if you indeed make a change).

Glad to hear your part hunting went well.

I read back a bit again on the transformer - thanks for pointing that out.  My line AC is rock solid year-round at 115V, so maybe I'm in good shape with the assigned SumR?  My readback indicated that maybe a 28-0-28 version SumR would be ideal, or perhaps a different brand altogether.  Any consensus at this point in time?
 
BK

 

 

[runeight]

If your line voltage really is 115 and generally stays in that vicinity then the 30V SUMR is probably the right choice.

 

[sachu]

Yeah..even the stock hammonds will work great. 

 

[BoilermakerFan]

Quote:

Yeah..even the stock hammonds will work great. 

But do they hum along with your music? 

 

[sachu]

I will know possbly by tonight if there are any noise problems but Having used hammond transformers in other builds I have'nt noticed this yet.

 

[sachu]

Hmm
 
brought up both the boards and no dice.
 
Output shows 0 DC offset.
 
However, i am not able to bias up the output devices at all. Full turn towards either end of the trimpot gave me nothing.
 
Rails are steady at +/-30V.
 
Is the Vbe multiplier not setup correctly for the BJT version perhaps?

 

[runeight]

What value did you use for R17?

 

[sachu]

3.9k 

 

[runeight]

Well, the BJT Vbe circuit was set up nominally for MJE243/253 devices. If you are using these guys you should be able to get something to show. But if you're using other BJTs then it's hard to know.

 

[sachu]

Am using the Toshiba 2SC2232/968 devices..I do have the MJEs somewhere here..but it'd be a shame not to be able to run the toshibas in this amp. 
 
I know gurubhai is using them successfully in his EHHA1 BJT build.

 

[runeight]

Try reducing the 3k9 to 3k3. Then set the trimpot to its maximum resistance before firing up. This adjustment is non-linear so even 600R reduction can make a huge difference.