Scannermax 506s

[mixedgas]

I just ordered 20 pairs. These are a pretty good duplicate of 67xxx, except not very compact. These are the higher speed amp in the modification PDF.


Stiffler, I look at it a bit differently:

Clone Amps divide into four families: Poor copy, 68xx clones, 67xxx clones, and Custom Made.

Poor Copy: ie the lowest cost amps. If they were not such poorly made copies, they would do 30K, but some one wanted to save one dollar on the output stage, omitted a few potentiometers, and put no AGC circuit on the sensor drive to save maybe 50 cents. These do 14-20K. Usually in very low cost projectors, and often only running on 30-50 watt power supplies for BOTH channels.
Always missing parts to save money. Usually the holes and pads are on the boards for the missing parts.

6850 clones, are your classic 30K amp. Schematic is widely available etc. These amps had to have component changes to match the whole range of factory galvos. So when bought surplus or copied, there is a wide range of speeds. There was pretty much only one technique for tuning these. PITA to initially tune/calibrate if you do not have a test fixture.

67xxx clones have the notch filter, better linearity from better AGC, and a slightly different architecture, and the 68 watt output stage. If you want 40K, your looking for these. Schematic is not readily available. These can be tuned for different responses, ie speed, accuracy, settling time, depending on user needs.

Custom: Projector company starts from scratch and does a custom amp, HB, Pangolin, LSDI, Laserworld etc.... Often has bridged 120 watt output stage, Angle Intelligence, galvo protection features, DSP, etc.

Salty Robot: The speed limit on the amp is dependent on the galvo attached to it. If the galvo/mirror combination can do 40K, these amps can do 40K. Pangolin pushed these amps very fast in their modification PDF at small angle. However these are from a different vendor, but have the same parts and layout. I had a pair before Bill published the modification PDF and already had it use with 6810.

Steve

[SaltyRobot]

Understood Thank you for the clarification Steve. I commend you for putting this together for the community.

Now I am just hoping the 506s will be on par with my budget.

[mixedgas]

Understood Thank you for the clarification Steve. I commend you for putting this together for the community.

Now I am just hoping the 506s will be on par with my budget.

You should be "Out the Door" for around 350$ with these amps depending on mirror options and shipping, without PSUs. I saw an invoice for one pair, with Bill's Blessing, at Pangolin, in the low 200$ range. I'm sure Justin is determining the final price by now. It is worth it for the good bearings alone.

One other thing, on my bench I can starve the amps with current limiting power supplies, so if something is wrong I can mitigate or prevent damage to the 506s.

Yes, the SMT is easy, and with care one can make the cables, but the bench setup and "corporate knowledge" is expensive.

From my point of view, I can put the money in the IRA, and earn nothing in interest. Or I can take the risk, sell these, and get a better return on my investment for a little time. At least for a few months.


Steve

[SaltyRobot]

That's on par with my budget.

Do you have a recommendation for PSU? Proper specs and what not. I am going to assume +/- 24VDC @ 1.5A per channel.

[mixedgas]

We were offered the generic PSUs at ~26$ our cost per PSU, (delivered) with specs of -24V at one amp and +24V at 1.5 amps. I'd need to see some profit on top of that, for my time and money, so I doubt its a good idea for me to order them. I'd prefer something much beefier and add external stiffener caps of my own. I like Meanwells and Lambdas.

Each Galvo needs 5-6 amps peak and say 1.5 amps average. They idle at about 100-150 mA from EACH power supply.

Choose a pair of something beefy and add caps for the current peaking. Marlin P. Jones is one place to look. I often use home made analog supplies with dual 4 amp transformers, but I don't care about size.

Steve

[swamidog]

steve -

are you going to post a review of the 506's running off your TT amps?

We were offered the generic PSUs at ~26$ our cost per PSU, (delivered) with specs of -24V at one amp and +24V at 1.5 amps. I'd need to see some profit on top of that, for my time and money, so I doubt its a good idea for me to order them. I'd prefer something much beefier and add external stiffener caps of my own. I like Meanwells and Lambdas.

Each Galvo needs 5-6 amps peak and say 1.5 amps average. They idle at about 100-150 mA from EACH power supply.

Choose a pair of something beefy and add caps for the current peaking. Marlin P. Jones is one place to look. I often use home made analog supplies with dual 4 amp transformers, but I don't care about size.

Steve

[mixedgas]

Swami, the TT2 just arrived from Bill Benner's work bench after repairs. A review will be forthcoming if the fragile TT2 survived the return shipping. My TT2 has been on many tours in the UK before I purchased it. A 15V regulator let go, from a old solder joint, and there was thermal damage to one scanner when it slammed to one side.

I'm probably going to inspect every solder joint.

Purpose designed amps for these newer galvos will probably need to feature limiters or shutdown on failure of the feedback loop. Think of it as a "free" scanfail circuit. If the connector is partially seated, and the feedback loop is opened, the galvo will be slammed to one side. The Ohmic heating from this condition will eventually do damage. This is why 506 cabling must be very, very good. This is true of all Galvos, but the newer low impedance coils will heat rapidly. Users must take care with their cabling.

Steve

[swamidog]

ahh.. i didn't know it had been in "the shop" so long. i have a TT2 here, so.. just wondering.

Swami, the TT2 just arrived from Bill Benner's work bench after repairs. A review will be forthcoming if the fragile ole TT2 survived the return shipping. My T2 has been on a lot of tours before I purchased it. A 15V regulator let go, from a old solder joint, and there were minor issues with the cabling.

This is why I stress 506 cabling must be VERY good. A partially unseated connector on such a low impedance coil can cause damage if the feedback circuit cannot close the loop and the amplifier slams the galvo to one side.
This is true with ANY galvo, but 506 has a very low impedance and Ohmic heating will eventually cause damage.


Steve

[mixedgas]

I'm a honest guy. I try to not take orders until I have stock. So those whom are in a hurry to order a pair, I'll put you on the reserve list. But I will not accept payment until I have the amps in hand. I've already had people try to Paypal me. I appreciate the effort, but lets not jump the gun. The order was placed this morning. The money gets to the supplier on Saturday, US Eastern time.

Steve

[mixedgas]

Three pairs out of the first 20 are already reserved. Let me know via PM if you wish to be on the reserve list.

Steve