sorenb

Circlotron Driver board from the Group Buy is working. As I'd like to test as much as possible before connecting everything, I'd decided to hook the driver up as an amp. The Carbon V5 and Circlotron driver board are very similar although there are a number of differences that require a bit of tweaking to make it work. The biggest difference is in the servo part of the driver board and since the driver board is missing the A06 - controlling the current in the tail of the output stage directly from the opto - it is probably not possible to run the output stage at 20mA as it will exceed the opto current capabilities. The pic shows (I believe) everything needed to 'convert' the driver into an amp - I haven't tried to get the servo to work though. The important alterations is: (not including servo - amp only) NOT populating the 10k/10uF besides the opto terminal (until it is actually gonna be used that is) parallel the 500ohm in the tail of the output stage with 150ohm or thereabouts (I just solder one on top - easy to remove again) adding 2x (100k + 100k) for feedback. adding 2x 5k1 ballast resistors to the output This is as I hook'ed it up, and dialed it in for 20mA operation - has ran for some days 24x7 without any problems. For the servo to work a few changes in addition to the picture above is needed: the opto has leg2 tied to GND - this trace needs to be cut. Remove: the 47uF between the opto leg1 and leg2, and 5k resistor between OpAmp leg6 and opto log1 Add: 1uF between OpAmp leg6 and leg2, 200ohm between OpAmp leg6 and opto leg 2, and GND to opto leg1

the "Kontakt Chemie" stuff is about 50% IPA. The Kontakt Chemie seems to work ok, but needs, as McLean mentioned, There seems to be consensus that the proper way to remove flux residue is a combination of very clean IPA >99% and some brushing. My concern is, as "muskyhuntr" says: "Otherwise, you are just rearranging the residue that's on the board" ... some has suggested rinsing using deionized water and blowing off with a heat gun.

Thanks....I've use this one ...doesn't tell what the magic solution comprises, but it surely smells like isopropanol ....seems to work ok

what would be a recommended way of cleaning a pcb from flux residue? do you test your pcbs with an isolation tester?

if of any help, I've collected the interest in buying LSK389 here

Your board seems filled with flux residue ... did you, or the skilled someone, clean the boards before use? The soldering seems like it could be enhanced a bit also - might be the light and how the picture was taken ...

bought 20 recently with someoneelse and paid well above 2,5USD

at $2.50 I'd take another 40

...the stth512 has 2V drop, and you have excatly 4V after rectifying ....and you ac is 450V .... I'd try if the connector terminal for the AC is ok?

massive achievement! I guess a thorough and careful approach pays off ;o)

E = V/d

A Carbon in disguise of a T2, expect a beasty looking Carbon ;o)

Will do, but its probably gonna take a while. I've finished all HV900 by now, and had them up and running in sets with 20kohm load for about four hours per set. Both transformer and angle brackets only get lukewarm.

Nice write up. But isn't it like comparing oranges to apples? having three different amps powered from three different PSU's? To my ears the PSU has quite an impact to the final sound from the amp.

how accurate does the 900V has to be? I guess the HV900 should be equal to the drop across the positive HV rail and negative HV rail? does it have to be accurate, or is is just lowest denominator that rules? Running both HV900 with 20k load for some hours, having monitoring of the drop across the SiC's, and it seems to fluktuate about 10V, and an average of 60V ... could one choose lower secondaries e.g.360vac rather? The ToroIDY 250VA (4x380 VAC) runs lukewarm and silent, so I guess 250VA is adequate but cannot be less. When loaded secondaries drop to +372VAC (230V mains)

The HV900 boards (from the Circlotron Group Buy) is working Has loaded it with 20k. When powering up, the amp-meter max out for a few secs, then drops to approx 1A, and finally settles at 180mA. Using a 250VA from ToroIDY seems to run cool and silent.

Group buy from PCBNet (same as Carbon and Circlotron Group Buy) for boards > 40. State your interest here A table and a modular graphic for easier overview of the various Golden Reference PSU boards and their function: The color scheme is the same used in the modular picture below. Options, each representing a full PSU everything needed for an amp (in the spreadsheet one can choose either): Option 1: Contains HV+/-, LV+/- and PRO BIAS. Option 2: As Option 1, but “Split” into two separate boards, making mounting more versatile. (Skinny and FAT contains the same, but Skinny is rectangular shape wheres FAT is sqarish) Option 3: Separate boards for each HV rail, LV rail and BIAS board (containing both PRO and NB BIAS), a total of five boards, and chassie mount caps. Option 4: ONLY low voltage - contains the Golden Reference Low Voltage, for those who wants the absolute best low voltage PSU. There are of course several other combinations possible. The "FAT" are squarish with transistors mounting along the long side. Both sides > 2U. The "Skinny" is rectangular with transistor mounting along the short side which is < 2U (thus can be mounted upright in a 2U chassie), /S Thanks Jay

if your chassie is 2U or even less you actually need the Golden Reference Single , or Single NoCaps board

oh, I get it CC stands for Clearly Cavalli ...your going 1mm PCBs and so forth ...

Probably "Cascoded CCS" ... the Carbon boards I bought from Spritzer didn't have cascoded CCS and didn't have opto coupler in the servo as the Carbon v5 from mwl168 group buy have. The Spritzer board does have extensive ground plane which the Carbon v5 doesn't. I guess the Carbon CC will be pretty close to the Insanity one (but probably not sporting the GR LV) ...

I have a 289 and find it slow in boot'ing....so usually I use an old 87 rather ....in rgrds to Brymen ...I have one too, not impressed, a Bryman 867 (not recommended) ...it works but damn slow in readings ... Stay away from advanced multimeters, what you get isn't worth the extra ...

I find that I often need at least two ...either for current/voltage ....or simply hook'ing one up monitoring a specific component and it's handy to have another to poke around with ... it doesn't have to be TOTL multimeters .... but I'd prefere known brand multimeters In rgrds to the thread starter question; the advice aimed at getting real experience ... something goes wrong, why? in trying to figure it out the theory comes in handy ... AoE is fine .... but like reading a Haynes does make you a qualified mechanic reading AoE doesn't necessary makes you grasp electronics

Buy two multimeters and a soldering iron - build a few small projects and hope for that something goes wrong and you need to troubleshoot ...

US: Everything has been shipped (missing a few that has not yet returned their shipping address). For non-US: only two is not shipped due to either missing shipping address or missing 470uF caps: the last batch has not yet arrived. /S

US participants: this will ship from Maryland no later than Wednesday this week: /S