Nearing completion and noticed looking back at a pic of my original board that the coupling caps were .47uF. What did you find since that led you to the current .22uF?
In most use cases either value will work fine. The SSE has been built many different ways by many different builders. Many were a first time build of an SE amp and budget parts were often involved. This often meant budget friendly small OPT's with limited bass response. When someone connects an SSE or any tube amp into a Home Theater system that plays movies containing lots of Low Frequency Effects or Low Frequency Energy AND that amp uses small OPT's, a large value coupling cap can present enough LFE into the OPT to cause saturation. When the OPT saturates, it behaves like a short or very low impedance causing the tube current to skyrocket. The result is distortion of all the signal at the time, and extended operation in this manner will shorten the life of the output tubes.
I have also seen some DIY phono stages that pass low frequency well enough that a warped record can cause a similar saturation effect.
In either case reducing the size of the coupling cap will roll off the LFE making the amp actually sound better when pushed hard. I see no issue with a .47uF in an amp that uses a large OPT like the Hammond 1628SEA or the Edcor CXSE-25 series. I used a .22 uF in amps that used an OPT weighing from 3 to 6 pounds like the GXSE series and often used a .1 uF in amps with the little open frame Edcors or the Hammond 125CSE.
If you were happy with the way your SSE played there is no reason to change them.
Thanks. I am using the GXSE and have JBLs so I'll stay with the .22s.
You'll see I ordered another board yesterday. The years old one I'm using is fine but I heard it was your birthday ;-)
Looking forward though to having a shiny new one without burn marks on some of the eyelets from having too much fun with it.
Happy Birthday,
Bill
You'll see I ordered another board yesterday. The years old one I'm using is fine but I heard it was your birthday ;-)
Looking forward though to having a shiny new one without burn marks on some of the eyelets from having too much fun with it.
Happy Birthday,
Bill
I have a problem with the TSE (2A3). A faulty rectifier (present day BRIMAR GZ34) shorted and blew the fuse. After replacing the fuse, it blew again when I switched it on. I suspect the transformer is busted as well.
I'll be measuring the mains trafo for resistance & shorts this weekend. Can someone help understand what else I should look for? Should I look for any part on the board as well ?
P.S: It will do you good to stay away from these new Brimar's, they're crap. This amp has less than 400hrs and is running at 300 B+ (60ma).
I'll be measuring the mains trafo for resistance & shorts this weekend. Can someone help understand what else I should look for? Should I look for any part on the board as well ?
P.S: It will do you good to stay away from these new Brimar's, they're crap. This amp has less than 400hrs and is running at 300 B+ (60ma).
I ordered most parts from Mouser today, however the V-Reg (IC29502WT) and FETs (STF3LN80K5) were out of stock. I checked Digi Key and found the same.
While searching for the V reg, I ran across a recomendation of the TI TPS756XX as a replacement. I finally found two TPS75601KC at Arrow and ordered them.
I will post how/if they work.
Anyone have recomendations for the FETs?
While searching for the V reg, I ran across a recomendation of the TI TPS756XX as a replacement. I finally found two TPS75601KC at Arrow and ordered them.
I will post how/if they work.
Anyone have recomendations for the FETs?
After reading the full datasheet, I have come to the conclusion the TI part won't work. It's Vin is much too low compared to the Microchip part. The TI part is pin and function compatible but not voltage compatable. It is closer to the MIC37xxx LDO.
Sorry for the slow reply. I have been busy trying unsuccessfully to melt some tubes. I did however squeeze 200 watts from one pair of 26HU5's without melting them, and I didn't need to fire up the power supply that eats parts for breakfast.
The TI part may work if you are building a 2A3 or 45 based amp since the raw supply to the regulator in a 2.5 volt configuration is 3 to 3.5 volts. I have not tried them though. Microchip bought Micrel several years ago. The MIC29502WT is an old Micrel part. The Micrel parts can often be found on Ebay. I got two from a supplier that I have used before, and they work fine. The Microchip MIC29503WT will also work. Look back at post #1197 in this thread for the discussion and testing of these parts with part numbers.
The TI part may work if you are building a 2A3 or 45 based amp since the raw supply to the regulator in a 2.5 volt configuration is 3 to 3.5 volts. I have not tried them though. Microchip bought Micrel several years ago. The MIC29502WT is an old Micrel part. The Micrel parts can often be found on Ebay. I got two from a supplier that I have used before, and they work fine. The Microchip MIC29503WT will also work. Look back at post #1197 in this thread for the discussion and testing of these parts with part numbers.
Thanks George. I read the whole thread the last couple of nights (Probably retained too little from reading past midnight).
I will go back to 1197.
The MIC29502WT is on back-order till June IIRC at Mouser.
I have two of the TI parts coming so I will test with them to see if they can hold up for 5V at 2.4A with resistive load.
I will go back to 1197.
The MIC29502WT is on back-order till June IIRC at Mouser.
I have two of the TI parts coming so I will test with them to see if they can hold up for 5V at 2.4A with resistive load.
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Rather than taking a chance on using the 10m45s from the old SSE board I've found that the part is back-orderd for over a year. IXCP10M90S should be no problem, yes?
Drat! I went right back yesterday after posting the question thinking your answer would tell me whether I could use them, it's only 10 bucks, and they were gone. 360 in stock to zero in 5 minutes.
I read somewhere the Russians were buying washing machines to scavenge the chips for missile parts. I wonder if I should buy a few?
Look at post #34 in the 10M45S thread. All of those alternative parts have been tested and confirmed to work fine in an SSE. All are still in stock in either Mouser or Digikey. The 500 volt versions of the 1000 volt parts should work too, but I have not tested them, since I didn't have them here. (substitute a 50 for the 100 in the part number).
If I had to pick one, I would choose the IXTP1R6N100D2, only because I spent the most time with them and it's $3.32.
https://www.diyaudio.com/community/threads/10m45s.390771/page-2
If I had to pick one, I would choose the IXTP1R6N100D2, only because I spent the most time with them and it's $3.32.
https://www.diyaudio.com/community/threads/10m45s.390771/page-2
Beautiful build!
Am I right to assume you set up the Maida regulator as a choke?
How did you control the voltage output?
Now, if the boards make it past the Moundsville post office, I should have all the parts coming.
It left the Moundsville post office the day it was picked up. The black hole where mail checks in and may or may not appear somewhere else in in Pittsburgh. I have noticed that the USPS has really screwed up a lot in the last month or two. Your board should be in your hands now. That makes three times in 40 days where a "2 or 3 day" delivery time was more like a week or three, with zero tracking.
A few missing boards have put Tubelab in the red for 2022, but the absolute deal breaker is that they have lost a check which carried my entire 401K funds in a rollover to an IRA. Things will get ugly if the 60 day limit arrives before I can a replacement check issued. The USPS will not even call it missing for 30 days after the mailing date.
If the USPS lost my 401k funds, that would let me get really mad.
Our local USPS service has been really spotty as of late. We had a new kid filling in for our regular carrier last summer. This kid delivered our neighbor's packages and mail twice in one week. I took them to their proper address, but refused the third time and called the supervisor. He kept telling me the kid was new and it was difficult to hire anybody.
We recently ordered some type of pressure cooker from Amazon for a birthday present. The box looked fine outside, but the cooker was dented in two places when we opened the box. So, Amazon also has a problem.
Our local USPS service has been really spotty as of late. We had a new kid filling in for our regular carrier last summer. This kid delivered our neighbor's packages and mail twice in one week. I took them to their proper address, but refused the third time and called the supervisor. He kept telling me the kid was new and it was difficult to hire anybody.
We recently ordered some type of pressure cooker from Amazon for a birthday present. The box looked fine outside, but the cooker was dented in two places when we opened the box. So, Amazon also has a problem.
I know I should be more patient, but when the tracking is showing no progress whatsoever, I start to worry.
But I have the boards now and they made it through in good shape! Beautiful even!
Your lost check case would have driven me mad for sure.