Babelfish M25, SissySIT - general building tips and tricks

Official Court Jester
Joined 2003
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btw.

just arrived two days ago :clown:

one piece with FW form factor , for one Greedy Boy having FW case clone from ebay (and I know that everyone who bought those , did that as Kudos to Pa , even if trading with some damn Leacher)

.... and bunch of regular pcbs
 

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:) thanks ZM - I am trying to save you from fools like me

The channel that is causing most problem - current with zero offset is 2.6A



This channel biases at 2A and zeros offset without changing R18/19




thank you again ..dB


EDIT - this was before I removed D1 / D2 which are now gone
 
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btw.

just arrived two days ago :clown:

one piece with FW form factor , for one Greedy Boy having FW case clone from ebay (and I know that everyone who bought those , did that as Kudos to Pa , even if trading with some damn Leacher)

.... and bunch of regular pcbs

very nice !

I would absolutely do this as a tribute to Pa if I was starting fresh - didn't see those FW case clones until last week.

..dB
 
Will go test diodes

Used the packet of parts that you sent - confirmed resistance of resistors with DMM before starting build. All parts as supplied from "the factory"

I have since changed R18 / R19 in the right channel only - this was to allow the output to be zeroed.

..dB
 
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Joined 2003
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do not change neither opto nor ACS

post proper pictures of both channels so I/we can see is there some mistake in parts placement or orientation

in few days I'll start here (or on my blog) proper and full photo-tutorial of SissySIT making , trying to point not just on specific issues with this amp , but also to some general things

however , for your specific case , posting set of proper pictures is best way

Perfect...my SITs should be arriving first of week. Heaven knows I need all the help I can get.

Anyone know source for those blue brick caps? I have yellow axil version I got off ebay, but would like to procure a small stash of these. I'm sure my kit has them from zen, although havent checked.

Russellc
 
Member
Joined 2008
Paid Member
I usually do the same as dBel and build my own chassis from scratch. Unfortunately, I’m pulling my hair out trying to finish a dipole bass project that I can’t get past the aesthetic stuff on while I watch you guys move forward.

I’m starting to think about buying a finished chassis that I may pretty up with my own faceplate. Are these the chassis you guys are talking about? One had a negative review about quality and missing parts.

Class PASS XA 30.5 hi-end full Aluminum Amplifier Chassis Case box 430*430*170mm | eBay

Big Aluminum Chassis PASS Class A Power Amplifier Enclosure DIY Case Hi-End Box 978078957307 | eBay
 
The one I had seen was a clone of the First watt, any of those would do very nicely.

The other ones I looked at were not specific to PASS.

High-End Aluminum Chassis Power Amplifier Case Audio DIY Cabinet Silver / Black 520516296839 | eBay


High-End Aluminum Chassis Power Amplifier Case Audio DIY Cabinet Silver / Black 520516296839 | eBay

This is the FW clone but it is sold out.

CLASS-A AMPLIFIER ENCLOSURE F1-F7, M2, J2, VFET, NUTUBE, 2SK82, 2SJ28, J112 | eBay



$400-$500 for a chassis is not unreasonable but I hate the idea of supporting leaches that benefit off Pa.

.. dB
 
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Joined 2012
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I purchased a WA68 chassis from an AliExpress merchant for my SissySit.

Buy wa68 and get free shipping on AliExpress.com

It says free shipping, but not true.

The chassis is big enough to stack two Antek AS-3218 transformers for dual mono. The internal dimensions are 330mm wide x 400mm deep x 144mm high. The top cover plate has cooling slots but the bottom plate does not. The back plate does not have any holes for any connectors.

I drilled and cut my own holes for RCA. speaker, fuse, and IEC connectors. I also drilled air holes in the bottom plate for cooling, and holes in the front panel for two power switches.

I had previously purchase two amplifier chassis and one preamp chassis from AliExpress mechants with DHL courier shipping, all with no problems. However with this purchase, I had paid for DHL courier shipping and the mechant, Hengfeng Audio Store, did not ship it by DHL. In the end it took nearly six weeks for shipping. All of my previous purchases were shipped DHL and were in my hands approximately two weeks after ordering. It usually took about a week or so for the package to be received by DHL and then only two to three days for shipping from China to Vancouver.

So this last shipment was a bit of a problem, but the chassis itself is to my expectations. This merchant's price at the time was considerably lower than his competitors, so I suppose that was the reason he did not ship it with DHL. At least I ordered it way before I needed it so it did not slow me down.

One thing though, Chinese New Year is next week so there may be some delay before shipments are made.

Here is a picture of the my SissySit in progress:
 

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