[ruZZ.il]

 

[naamanf]

Quote:

Originally Posted by cetoole /img/forum/go_quote.gif I have received the PCBs and padded envelopes, and purchased the shipping and return labels. I expect to have the first batch out Monday.

 

[MrMajestic2]

Quote:

Originally Posted by cetoole /img/forum/go_quote.gif I have received the PCBs and padded envelopes, and purchased the shipping and return labels. I expect to have the first batch out Monday.

Will you marry me Cetoole

 

[Ech0]

Quote:

Originally Posted by cetoole /img/forum/go_quote.gif I have received the PCBs and padded envelopes, and purchased the shipping and return labels. I expect to have the first batch out Monday.

WooooHooooooo!

 

[MrMajestic2]

Parts are slowly trickling in for my Max builds. Man, the Black Gate NX-HiQ 0.47uf/50v are tiny. Half the fun is sourcing parts and unpacking boxes, right?

 

[amphead]

Quote:

Originally Posted by cetoole /img/forum/go_quote.gif I have received the PCBs and padded envelopes, and purchased the shipping and return labels. I expect to have the first batch out Monday.

My brain is salivating at the whole idea of building this beauty!

 

[kklee]

All of my parts have come in, now all I need are the PCB's and I can get building!

 

[Troyhoot]

The Joys of matching transistors

Been working on these for couple days now and I have a couple concerns/questions.

I have ran through the 5088's twice and they seemed to level out nicely after the second run. I think i can make 3 pairs within 1 of each other. Going to run through the close ones at least a couple times before final assembly im sure.

Now the 5087's, after 3 runs they are still going down each test. So im a little concerned if they will ever level out.

So my questions..
1. How many times is resonable to test the 5087 to get them to level out.
2. How close do the sets need to be to each other ? ie: can the 2 sets for the ccs be 20-50 points off the 3 sets for the buffers ?

Since my parts are starting to trickle in im getting excited. Almost as excited as I am about my wife being 8 1/2 months pregnant

Might get to work on it before we go to the hospital ahaha At least it will give me something to do while the baby takes cat naps. Just hope percy gets back from vaction this weekend so I can get my caps and a few resistors ordered.

 

[tomb]

Quote:

Originally Posted by Troyhoot /img/forum/go_quote.gif The Joys of matching transistors Been working on these for couple days now and I have a couple concerns/questions. I have ran through the 5088's twice and they seemed to level out nicely after the second run. I think i can make 3 pairs within 1 of each other. Going to run through the close ones at least a couple times before final assembly im sure. Now the 5087's, after 3 runs they are still going down each test. So im a little concerned if they will ever level out.

Don't leave them in forever. Yes, they change as the small amount of current from the meter is applied, but a couple of seconds should be enough, I think. The idea is to "match," and if you start holding some in longer, then you should do the others that way, too. Pretty soon it may get out of control and you'd be better off not matching at all. Extreme, for sure, but just trying to illustrate the goal. Ultimately, the large output blocking caps are going to stop all offset.

The most important matching is actually the two in the CCS for each tube, IMHO.

Quote:

So my questions.. 1. How many times is resonable to test the 5087 to get them to level out.

I think twice is enough.

Quote:

2. How close do the sets need to be to each other ? ie: can the 2 sets for the ccs be 20-50 points off the 3 sets for the buffers ?

Sounds pretty close to me. I've seen the complementary pairs no closer than about 100 before (should've bought more). You do want to pick two sets that are the closest, however. Yes, the CCS's have no relationship to the DB's. There is no need to get them the same. As mentioned above, the two transistors for each CCS are probably the most important ones to match (among the four) on the whole board, however.

Quote:

Since my parts are starting to trickle in im getting excited. Almost as excited as I am about my wife being 8 1/2 months pregnant Might get to work on it before we go to the hospital ahaha At least it will give me something to do while the baby takes cat naps. Just hope percy gets back from vaction this weekend so I can get my caps and a few resistors ordered.

I hope you get it built before 9 mos is up. You may not have much of a chance for awhile after that. Or maybe the 3rd or 4th time you get up during the night, you can work on the MAX instead of taking the trouble to go back to bed.

Seriously, best wishes on the baby.

 

[Troyhoot]

Thanks TomB. That helped alot. I was leaving them in till the meter stoped dropping instead of just a few seconds. Made a big difference. Now I have plenty for the CCS at 347, and the buffers at 351 and 381 respectively. Thats about as close as I could get with the two types with the 60 each I ordered.

My tubes came in from RadioDaze today too. Real pleased with them as a vender. I asked for same brand sets and they sent me RCA 12fk6, Raytheon 12ae6a, and Tung-Sol 12fm6. Shipping was fast. Packaging was great too. They answered an email in less then an hour before my order too. Ill use them again im sure.

 

[tomb]

Wow - those trannies all sound really close. You won't have any trouble getting those DB's balanced out!

Yes, the Radio Daze guys are pretty good. Seeing their packaging when my tubes were delivered for the first time sold me, too! (besides their price and selection, which was already great)

 

[babbkutz@comcast]

tomb......2 questions relating to the casework on the MAX site......(1) part used for the mini plug (female) on the front panel? and (2) parts used for the test points on the rear.......details on connection to the board........Thanks

 

[tomb]

Quote:

Originally Posted by babbkutz@comcast /img/forum/go_quote.gif tomb......2 questions relating to the casework on the MAX site......(1) part used for the mini plug (female) on the front panel?

Mouser #161-7400-EX. Note that this is actually a "commodity" part and is sold under many labels, including Philmore. I've bought many of them at Fry's.
Quote:

and (2) parts used for the test points on the rear

Mouser Part #530-105-0801-1. This one is white, there are different part numbers for other colors. Some may call these cheap - and they are - but they are entirely functional for me, are totally insulated being plastic, and have a crimp/solder connection. Higher quality tip jacks sometimes used by others have one of those p2p studs that has to be wire wrapped - yuck.

I actually bought these in bulk from a local electronics store that was relinqushing their storefront building. I only got the white ones, and then dyed them in the sink with grocery store RIT dye - could've made stripes if I had masked them properly.

Quote:

.......details on connection to the board........Thanks

I have been remiss in finishing pics and text on wiring details - I will try to complete that today. If you are referring to the specific wiring for these tip jacks, I simply soldered them into the bottom of the board at all the test positions. The center gray jack is the ground, the voltage adjust jack is off to the side away from the others. Then the first two on either side are the tube bias - L/R. Then DB bias - L/R, A and B. Of course, you simply use the L or R tube bias test point as the reference for the DB test points for L or R, respectively.

Others have remarked that there's not enough room between the jacks for typical DMM test probes, but all you need do is plug in the COM jack all the way into the requisite tip jack. Then, even if the test point jack is immediately adjacent, only a partial insertion is plenty to make a measurement - and to stay in place.

The downside to this is that the tip jacks are soldered to the board, and are installed into the backplate from the outside. This means the backplate is forever attached to the bottom of the board. Accordingly, I built in plenty of slack to remove any issues with ever removing the board, endplate, etc. as necessary:

This pic is on the MAX website at "Construction -> Casework -> Wiring&Assembly - Pt 3".

EDIT: I actually positioned the tip jacks a little too close to the bottom of the case. The jacks are so close that the nuts match up flat-to-flat. Unfortunately, the nut corners were far enough down that they were touching the bottom of the case and interfered with closing everything up. I sort of forced the nuts into an inbetween position and finally got everything to fit. I think this happened because the metal is quite a bit thicker on the MAX Hammond case compared to smaller Hammond cases - the clearance was that close. I need to adjust the CAD file drawing on the site accordingly, so keep that in mind.

 

[n_maher]

Tom,

That's just a heck of a clean build you did there. I start drooling every time I look at those pictures!

 

[tomb]

Thanks, Nate! That's high praise coming from the Uber Millett Guru himself.

EDIT: BTW, that B22 pic you put in Clutz's Amp section thread is incredible!