I have recently been changing my system from a 2 way passive crossover horn system to 4-way active system using a DEQX processor. Amazing technology, but that’s a topic unto itself.
Over the years I have used a Wellborne Laruel 300B amp I built 20 years ago, a 45 amp, and a Pass Aleph 3. I never should have sold that Aleph 3. I bought some amps to go active, plus I just built an Amp Camp 1.6 Stereo amp over the holidays. It was a fun build, and it was nice to fire up the soldering iron. Great build guide, too!
The purpose of this post is the other 2 amps I got: used Aleph Mini Clones. Both Alephs make some noise, one more than the other. I started down the research bunny holes on here and it looks like I bought some used Rawson builds. What the amps do well, they do extremely well. They sound great. However, there are some problems to be solved, and that’s where I’m looking for insight.
I’ll call them Tall Boy and Shorty because one is in a taller chassis than the other.
Symptoms – Noise & Hum
Tall Boy
Short the inputs – no speaker hum
Open inputs – hum
Inputs connected to Sonos source – much less hum, but not dead quiet.
Shorty
Short the inputs – no speaker hum
Open inputs – hummmmm – I don’t have a scope, but measured using OmniMic on my old horns. Biggest spike is at 240 Hz, with spikes at 60, 120, 360.
Inputs connected to Sonos source – less hum, noisier than tallboy
Diagnosis
I opened up both amps and looked around. I also did some searching on here to get a sense of what I’m looking at.
Power Supplies – big deviation from Pass design.
Both Amps use Hammond Transform 25VCT and one rectifier bridge. “As-Built” pix are attached below. Neither had the ground on the plug connected, I fixed that. Wires looks like they’re from the scrap heap. No bleeder resistors. In fact, no resistors at all. So it’s not a CRC, it’s only C. Tall Boy uses 6x 22,000 uF 25V Nichicons. Shorty uses 6x 15,000uF 25V caps. Shorty has 1 thermistor, Tall Boy has none. Both amps have +17V / -17V rails.
Amp Circuits
Tall Boy uses 327791 Boards.
This is a headscratcher - There is a 2.7 Ohm 5% 3.75W Resistor between board and negative speaker output terminal. Transistors look to be
Qty 2 - 2SJ74
Qty 1 – ZTX550
Qty 2 – MPSA18
Qty 2 – IRFP240
The only thing supporting the boards is the MOSFETS. There are no standoffs.
The leads on the smaller transistors are must be bent to go into the appropriate holes on the board. This is different from the drop-in “plug and play” boards on the Amp Camp Amp I just built. Probably just fine, but I found it a bit odd to see the legs twisted a bit, not stick straight.
DC Offset – Measured at speaker terminals = 43mV (Left), 104 mV (Right)
Voltage across 0.47Ohm R =0.648V
Therefore Bias = 1.378A
Shorty looks like it uses BrainGT boards. That’s what I can guess from searching threads here.
Transistors look to be
Qty 2 - 2SJ74
Qty 1 – ZTX550
Qty 2 – MPSA18
Qty 2 – IRFP240
The only thing supporting the boards is the MOSFETS. There are no standoffs.
Same thing on the smaller transistor leads as above.
DC Offset – Measured at speaker terminals = 34mV (Left), 37mV (Right)
Voltage across 0.47Ohm R (R27/28) = 0.637V
Therefore Bias = 1.355A
Questions / Potential mods:
Total Power Supply Rebuild – looking for suggestions / tips
DC offset adjustment - replace R8 with SP064W-500-ND (500 Ohms 0.5W, 1/2W multiturn pot)
Bias Adjust – replace R13 with SP064W-200K-ND (200 kOhms 0.5W, 1/2W multiturn pot)
My Amp Camp Amp is pictured, too. That was a really fun project!
Over the years I have used a Wellborne Laruel 300B amp I built 20 years ago, a 45 amp, and a Pass Aleph 3. I never should have sold that Aleph 3. I bought some amps to go active, plus I just built an Amp Camp 1.6 Stereo amp over the holidays. It was a fun build, and it was nice to fire up the soldering iron. Great build guide, too!
The purpose of this post is the other 2 amps I got: used Aleph Mini Clones. Both Alephs make some noise, one more than the other. I started down the research bunny holes on here and it looks like I bought some used Rawson builds. What the amps do well, they do extremely well. They sound great. However, there are some problems to be solved, and that’s where I’m looking for insight.
I’ll call them Tall Boy and Shorty because one is in a taller chassis than the other.
Symptoms – Noise & Hum
Tall Boy
Short the inputs – no speaker hum
Open inputs – hum
Inputs connected to Sonos source – much less hum, but not dead quiet.
Shorty
Short the inputs – no speaker hum
Open inputs – hummmmm – I don’t have a scope, but measured using OmniMic on my old horns. Biggest spike is at 240 Hz, with spikes at 60, 120, 360.
Inputs connected to Sonos source – less hum, noisier than tallboy
Diagnosis
I opened up both amps and looked around. I also did some searching on here to get a sense of what I’m looking at.
Power Supplies – big deviation from Pass design.
Both Amps use Hammond Transform 25VCT and one rectifier bridge. “As-Built” pix are attached below. Neither had the ground on the plug connected, I fixed that. Wires looks like they’re from the scrap heap. No bleeder resistors. In fact, no resistors at all. So it’s not a CRC, it’s only C. Tall Boy uses 6x 22,000 uF 25V Nichicons. Shorty uses 6x 15,000uF 25V caps. Shorty has 1 thermistor, Tall Boy has none. Both amps have +17V / -17V rails.
Amp Circuits
Tall Boy uses 327791 Boards.
This is a headscratcher - There is a 2.7 Ohm 5% 3.75W Resistor between board and negative speaker output terminal. Transistors look to be
Qty 2 - 2SJ74
Qty 1 – ZTX550
Qty 2 – MPSA18
Qty 2 – IRFP240
The only thing supporting the boards is the MOSFETS. There are no standoffs.
The leads on the smaller transistors are must be bent to go into the appropriate holes on the board. This is different from the drop-in “plug and play” boards on the Amp Camp Amp I just built. Probably just fine, but I found it a bit odd to see the legs twisted a bit, not stick straight.
DC Offset – Measured at speaker terminals = 43mV (Left), 104 mV (Right)
Voltage across 0.47Ohm R =0.648V
Therefore Bias = 1.378A
Shorty looks like it uses BrainGT boards. That’s what I can guess from searching threads here.
Transistors look to be
Qty 2 - 2SJ74
Qty 1 – ZTX550
Qty 2 – MPSA18
Qty 2 – IRFP240
The only thing supporting the boards is the MOSFETS. There are no standoffs.
Same thing on the smaller transistor leads as above.
DC Offset – Measured at speaker terminals = 34mV (Left), 37mV (Right)
Voltage across 0.47Ohm R (R27/28) = 0.637V
Therefore Bias = 1.355A
Questions / Potential mods:
Total Power Supply Rebuild – looking for suggestions / tips
DC offset adjustment - replace R8 with SP064W-500-ND (500 Ohms 0.5W, 1/2W multiturn pot)
Bias Adjust – replace R13 with SP064W-200K-ND (200 kOhms 0.5W, 1/2W multiturn pot)
My Amp Camp Amp is pictured, too. That was a really fun project!
Attachments
Just some random thoughts/comments...
Good thing you've made the safety earth connections. That was the first thing to do.
The legs are twisted because their pinouts are different from the mosfets, for example,
used originally on the BrianGT boards. Be careful you don't short out those parts.
I would rebuild the PS completely on PCBs into a CRC supply. You can reuse the
caps.
Please consider adding standoffs to the PCBs. I would also add the changes
to allow trimming of DC offsets.
Nice ACA build!
Good thing you've made the safety earth connections. That was the first thing to do.
The legs are twisted because their pinouts are different from the mosfets, for example,
used originally on the BrianGT boards. Be careful you don't short out those parts.
I would rebuild the PS completely on PCBs into a CRC supply. You can reuse the
caps.
Please consider adding standoffs to the PCBs. I would also add the changes
to allow trimming of DC offsets.
Nice ACA build!
agree with D
study schmtc of usual FW CRC supply , take good care of physical layout of cap bank - where input wires are connected , where output wires are connected and where is takeout for GND
besides that , ensure proper pcb fasteners , triple check all thermal interfaces , be sure to have big washers on mosfets , same as to have split washer on every bolt on every thermal interface , including Graetz bridges ...... I did change several of these , due to loosened bolt and bridge loosing cooling ....
you can see my (always twisted) logic here
study schmtc of usual FW CRC supply , take good care of physical layout of cap bank - where input wires are connected , where output wires are connected and where is takeout for GND
besides that , ensure proper pcb fasteners , triple check all thermal interfaces , be sure to have big washers on mosfets , same as to have split washer on every bolt on every thermal interface , including Graetz bridges ...... I did change several of these , due to loosened bolt and bridge loosing cooling ....
you can see my (always twisted) logic here
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The original Pass Labs Aleph 3 also used a single bridge rectifier and a C (not CRC) psu without bleeder resistors. It used 8 x 22000uF, so a bit more than these have.
The fact that they are using 2 x 2SJ74 makes them more like an Aleph J (JFet front end rather than 9610 mosfet used in original Aleph series).
Generic FW psu is a good choice as suggested by Dennis and Zen Mod.
If you look at the Aleph J schematic http://www.diyaudio.com/forums/atta...eph-j-universal-mounting-spec-aj-skema-bw.png the DC offset can be adjusted by R8 but the total resistance is R6 (562R) + R8 (0-500R). The fixed resistor is used together with a trimmer. The trimmer is as small as possible (let the fixed resistor dissipate most of the heat) but large enough to cover the range of values you might need.
If I remember correctly, there was only room for 1 resistor and no trrimmer on the BrianGT boards. If you replace the resistor that is on there now (what value is it?) by a 500R trimmer you will probably not have enough range. I would recommend the approach used in the store Aleph J, which is resistor + trimmer (probably best to use values in the Aleph J BOM). If you want to try trimmer only, you will probably need to go to 1k.
On the Aleph J, bias is adjusted using trimmer R7 (no fixed resistor in series). It is specified as 2k. Why would you use a 200k trimmer?
I did not look up the product numbers you mentioned but noticed they were not what is specified in the Aleph J BOM. Why deviate from the Aleph J BOM?
Hope this helps!
It's not clear how the part designation on his boards match up with say, the
standard Aleph-J schematics.
Agree that they are suppose to be mini AJ's. My suggestion to OP is to
refer first to the original AJ schematics and see how well things match up
(minus the obviously few output mosfets).
Question for OP: How much work are you willing to put into this? For example,
are you amenable to salvaging parts from the amp board and rebuilding on
new PCBs, and also do some mechanical work (drilling and tapping some new holes)?
Cheers,
Dennis
standard Aleph-J schematics.
Agree that they are suppose to be mini AJ's. My suggestion to OP is to
refer first to the original AJ schematics and see how well things match up
(minus the obviously few output mosfets).
Question for OP: How much work are you willing to put into this? For example,
are you amenable to salvaging parts from the amp board and rebuilding on
new PCBs, and also do some mechanical work (drilling and tapping some new holes)?
Cheers,
Dennis
Yes, I think they're supposed to be Mini-J's. I'll study up to see how they compare. Good call.
I'm willing to gut the thing and rework it. The PS should be straightfoward. Having just built Amp Camp Amps, and looking at these, the boards look to be similar in terms of complexity. The main difference here is drilling and tapping.
Right now my gut says build the Power Supplies and appropriately tweak DC Offset and Bias (if needed) and give them some run time. 10W range is plenty for my horns. If I could get my hands on the transistors I'd consider a 30W amp for my woofer.
AlbertNL,
Thanks for the insight - good read! I'm putting together bits and pieces as I comb through these pages. Before I order any trimmers I'll get a closer look at schematics and make sure I get the right values. Thanks for the reminder of fixed plus pot, not just relying on the pot by itself.
Thanks for the insight - good read! I'm putting together bits and pieces as I comb through these pages. Before I order any trimmers I'll get a closer look at schematics and make sure I get the right values. Thanks for the reminder of fixed plus pot, not just relying on the pot by itself.
Shorty's offsets, while not great, are minimally acceptable. May I suggest you
start with a new PS there, with thermistor between PS gnd and chassis and safety
earth, and see what improvements are achieved.
Can you check the value of the fuses? (Just in case it's something completely
inappropriate.)
Cheers,
Dennis
start with a new PS there, with thermistor between PS gnd and chassis and safety
earth, and see what improvements are achieved.
Can you check the value of the fuses? (Just in case it's something completely
inappropriate.)
Cheers,
Dennis
I'll check fuse values. Good idea. I checked that they're in there, but I may need a magnifying glass to read them.
Different question. I'm putting together a BOM for power supplies.
Thoughts on keeping the existing Hammond 25VCT transformer vs. going to a 2x15V 200VA AnTek? I need to make some measurements on chassis depth to see about a board plus toroidal xformer. 2x$32 + shipping isn't a killer, but I'd like to reuse what I can where possible.
I see some Pass Power Supply PCB's on Ebay that look like the exact design, I'm thinking of going for those.
Hard to tell the scale, but do you think one of the chassis can handle 4 channels of heat? If so, you could make one chassis for the amps and the other for the PSUs. Even quieter for your horns.
Edit - I might have a set of brianGT boards buried somewhere if you want to make it all the same. Mine are blue i think.
Edit - I might have a set of brianGT boards buried somewhere if you want to make it all the same. Mine are blue i think.
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I have spent time this week studying and documenting the boards in my amps. After doing all that, I found a goldmine in this thread.
Aleph with BrianGT boards - diyAudio
The spreadsheet that thread with cross references between Aleph J schematic, BrianGT Schematic, and BrianGT PCB label would have saved me hours. It is gold. I learned a lot in the process, though. The good news is that the spreadsheet an the schematic posted by bobodioulasso regarding using BrianGT’s boards for an Aleph J lined up with what I found. Once I moved on the green boards, that went super quick.
PDF/Pix are of:
My documented “As-Built” schematics for both amps, plus pix of boards with component locations. This will be useful for any work at the bench now or in the future.
Pix of schematics from bobodioulasso’s post. One is the Aleph J on BrianGT Boards. The other is titled “Aleph 30 mod” and had red X’s on parts not included.
Questions that I need input on:
- What is R0? I have a 3 Ohm R0 resistor on the BrianGT board amp on the board, and 2.7 Ohm from board to speaker negative terminal on the other amp. It is not on bobodioulasso’s build, and crossed out with a red X on the other schematic. I’m thinking I remove them… Thoughts?
-
My amps dosn’t have the R27 on the boards. It’s open. I understand that is used for setting Bias. Should I put in a 68.2k resistor? Bias now is at 1.378A on one amp, and 1.355A on the other. Maybe a non-issue. Thoughts or experience on leaving R27 out?
- bobodioulasso’s drawing shows R27 (on his drawing R13 68k2) with a dashed line. Any clue on what the dashed line is?
Since I'm going to get in and tweak, are there any parts on the boards that could benefit from premium parts? I could imagine caps are candidates. Any favorite flavors?
Open items:
- Swap R14 and R16 on “Shorty” amp. It appears they’re backwards
- Jumper SG to –IN on "Shorty"
- Address R27 68k2 resistor when I know the right thing to do.
- Address R0 / mystery 2.7Ohm resistor when I know the right thing to do.
- Order Parts and update
- CRC PS
- Pots for R8 (DC Offset Adjust)
- C6 10uF on “Shorty”
- 2.5A 250V fuses
@mpmarino - What would you want for those boards?
Aleph with BrianGT boards - diyAudio
The spreadsheet that thread with cross references between Aleph J schematic, BrianGT Schematic, and BrianGT PCB label would have saved me hours. It is gold. I learned a lot in the process, though. The good news is that the spreadsheet an the schematic posted by bobodioulasso regarding using BrianGT’s boards for an Aleph J lined up with what I found. Once I moved on the green boards, that went super quick.
PDF/Pix are of:
My documented “As-Built” schematics for both amps, plus pix of boards with component locations. This will be useful for any work at the bench now or in the future.
Pix of schematics from bobodioulasso’s post. One is the Aleph J on BrianGT Boards. The other is titled “Aleph 30 mod” and had red X’s on parts not included.
Questions that I need input on:
- What is R0? I have a 3 Ohm R0 resistor on the BrianGT board amp on the board, and 2.7 Ohm from board to speaker negative terminal on the other amp. It is not on bobodioulasso’s build, and crossed out with a red X on the other schematic. I’m thinking I remove them… Thoughts?
-
My amps dosn’t have the R27 on the boards. It’s open. I understand that is used for setting Bias. Should I put in a 68.2k resistor? Bias now is at 1.378A on one amp, and 1.355A on the other. Maybe a non-issue. Thoughts or experience on leaving R27 out?
- bobodioulasso’s drawing shows R27 (on his drawing R13 68k2) with a dashed line. Any clue on what the dashed line is?
Since I'm going to get in and tweak, are there any parts on the boards that could benefit from premium parts? I could imagine caps are candidates. Any favorite flavors?
Open items:
- Swap R14 and R16 on “Shorty” amp. It appears they’re backwards
- Jumper SG to –IN on "Shorty"
- Address R27 68k2 resistor when I know the right thing to do.
- Address R0 / mystery 2.7Ohm resistor when I know the right thing to do.
- Order Parts and update
- CRC PS
- Pots for R8 (DC Offset Adjust)
- C6 10uF on “Shorty”
- 2.5A 250V fuses
@mpmarino - What would you want for those boards?
Attachments
-
Aleph 30 mod.JPG -
aleph j brian gt bobodioulasso .JPG -
Tallboy Board As-Built-00a.pdf
-
Tallboy Schematic As-Built-00a.pdf
-
Shorty Board As-Built-00a.pdf
-
Shorty Schematic As-Built-00a.pdf
-
Shorty Schematic As-Built-00a.jpg -
Shorty Board As-Built-00a.jpg -
Tallboy Schematic As-Built-00a.jpg -
Tallboy Board As-Built-00a.jpg
Weekend progress.
I gutted "Shorty" amp. I installed transformers, bridges, and a terminal block with AC mains in, cap, thermistors.
I'm stuck on the PS boards until my PCB spacers show up. My first amazon order is apparently coming from China, because delivery date is weeks out. Ooops. I have a batch set to come in on Wednesday. Perfect timing from return from a short biz trip.
I made some updates on the amp PCBs, too. Updated 'lytic caps, added missing caps, installed pots for Bias and DC offset, and swapped the resistors that were backwards.
Hopefully by this weekend I can fire it up for testing.
I bought a tap set for this. My wife is already sick of the "I'll tap that" jokes.
I gutted "Shorty" amp. I installed transformers, bridges, and a terminal block with AC mains in, cap, thermistors.
I'm stuck on the PS boards until my PCB spacers show up. My first amazon order is apparently coming from China, because delivery date is weeks out. Ooops. I have a batch set to come in on Wednesday. Perfect timing from return from a short biz trip.
I made some updates on the amp PCBs, too. Updated 'lytic caps, added missing caps, installed pots for Bias and DC offset, and swapped the resistors that were backwards.
Hopefully by this weekend I can fire it up for testing.
I bought a tap set for this. My wife is already sick of the "I'll tap that" jokes.
Attachments
I rebuilt the “Shorty” amp – pic is below.
It tested the output on some cheap speakers, then hooked it up my eXemplar horns. Good news: the hum in the speaker output is tamed. Sound is great.
The bad news – these Hammond transformers buzz louder than original speaker hum.
Is this a normal thing for Hammonds? Could it be the wiring job, or layout? If you see the picture you can see the AC mains going to a terminal block, then a thermistor and wire going to each transfomer. I had an orange drop cap at the terminal block, but pulled it.
Thoughts on how to fix it? Real estate is tight in this chassis, I opted for the hammonds because I measured up and all of the torroid options I looked at were extremely tight squeezes.
Power supply voltage = +/- 20.3V (was +/-17V before mods)
DC Offset 25mV Left, 30mV Right (was 34mV / 37mV before mods)
Bias Voltage = .592V / 1.26A (was .637V / 1.355A before mods)
I haven’t played with pots to tune the bia or offset, I want to solve the buzz first.
It tested the output on some cheap speakers, then hooked it up my eXemplar horns. Good news: the hum in the speaker output is tamed. Sound is great.
The bad news – these Hammond transformers buzz louder than original speaker hum.
Is this a normal thing for Hammonds? Could it be the wiring job, or layout? If you see the picture you can see the AC mains going to a terminal block, then a thermistor and wire going to each transfomer. I had an orange drop cap at the terminal block, but pulled it.
Thoughts on how to fix it? Real estate is tight in this chassis, I opted for the hammonds because I measured up and all of the torroid options I looked at were extremely tight squeezes.
Power supply voltage = +/- 20.3V (was +/-17V before mods)
DC Offset 25mV Left, 30mV Right (was 34mV / 37mV before mods)
Bias Voltage = .592V / 1.26A (was .637V / 1.355A before mods)
I haven’t played with pots to tune the bia or offset, I want to solve the buzz first.
Attachments
MPMarino - thanks for the suggestion! I went to bed stumped about this, and woke up thinking about it. Your post got me inspired to try some things. After lunch I played around a bit.
- Transfomers out, no thermistors. Transformers still hum/buzz regardless of how I move them around.
- I found a corcom filter in my bag of tricks and thought "what the hell". I tried that between the switch/fuse and the transformers. Transformers still hum/buzz.
With the trannies out of the amp, it's quite easy to hear that it's the transfomers. And the speakers (in another room with long speaker cables) make great music. So it now comes down to figuring out the transfomers.
Before I bought the Hammonds I cut out circles the size of AnTek, Plitron, and Avel Lindberg torroids. The AnTek and Avels' won't fit on the bottom (traditional mounting) or standing up.
It looks like I could bolt a Plitron to the faceplate or maybe to an L bracket and have a couple millimeters to spare. Tight, but possible.
I could also try to put it on the bottom and move the PS boards perpendicular to their current configuration. I have a feeling the caps might not clear the binding posts or the amp boards. It would be a very tight squeeze.
Any other ideas on transformers? I'm assuming these won't work, so I'm looking for a "one and done" solution. 2x 15V or 16V or 18V @ 200VA-ish
- Transfomers out, no thermistors. Transformers still hum/buzz regardless of how I move them around.
- I found a corcom filter in my bag of tricks and thought "what the hell". I tried that between the switch/fuse and the transformers. Transformers still hum/buzz.
With the trannies out of the amp, it's quite easy to hear that it's the transfomers. And the speakers (in another room with long speaker cables) make great music. So it now comes down to figuring out the transfomers.
Before I bought the Hammonds I cut out circles the size of AnTek, Plitron, and Avel Lindberg torroids. The AnTek and Avels' won't fit on the bottom (traditional mounting) or standing up.
It looks like I could bolt a Plitron to the faceplate or maybe to an L bracket and have a couple millimeters to spare. Tight, but possible.
I could also try to put it on the bottom and move the PS boards perpendicular to their current configuration. I have a feeling the caps might not clear the binding posts or the amp boards. It would be a very tight squeeze.
Any other ideas on transformers? I'm assuming these won't work, so I'm looking for a "one and done" solution. 2x 15V or 16V or 18V @ 200VA-ish
Attachments
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Today's experiment.
I decided to try and go back to original transformer (25VCT) with single rectifier bridge into the new CRC filter. So center tap to star ground, + from bridge to V+ input on the boards, - to V-.
Fire it up.
+/- 16.9V to rails. Good. 0.1V drop with CRC filter compared to original.
Plays nice music.
Transformer doesn't buzz. But I hear hum from the speakers when music is paused. Back to the original problem.
That leads me to conclude the dual rectifier bridge setup is key for noise reduction. I saw that when reading here Dual Bridge Rectifiers in PSU - why?
Side note. With the bias pot in, not "freewheeling" as original, the bias voltage was pretty close to previous dual rectifier / transformer and higher voltage rails. Good to know that it's doing its job.
Here are some options I'm thinking about now;
- Get a Plitron, see if I can stuff it in
If not, get a new chassis to hold 2 torrids and use that to feed both of my Aleph Mini-J's.
- I could consider transplanting all the guts into an all-new properly sized chassis, but that's the high price solution. I want to make what I have work before I go that route.
Thoughts or advice?
I decided to try and go back to original transformer (25VCT) with single rectifier bridge into the new CRC filter. So center tap to star ground, + from bridge to V+ input on the boards, - to V-.
Fire it up.
+/- 16.9V to rails. Good. 0.1V drop with CRC filter compared to original.
Plays nice music.
Transformer doesn't buzz. But I hear hum from the speakers when music is paused. Back to the original problem.
That leads me to conclude the dual rectifier bridge setup is key for noise reduction. I saw that when reading here Dual Bridge Rectifiers in PSU - why?
Side note. With the bias pot in, not "freewheeling" as original, the bias voltage was pretty close to previous dual rectifier / transformer and higher voltage rails. Good to know that it's doing its job.
Here are some options I'm thinking about now;
- Get a Plitron, see if I can stuff it in
If not, get a new chassis to hold 2 torrids and use that to feed both of my Aleph Mini-J's.
- I could consider transplanting all the guts into an all-new properly sized chassis, but that's the high price solution. I want to make what I have work before I go that route.
Thoughts or advice?
Attachments
- Status
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