It is playing together with "Singing Bush". First I forgot to reverse the phase of speakers as Iron-Pre replaced Korg.
Then with 6 dB it is just enough. I will probably try out 12 dB later but for now I tried some Neutrik XLR to RCA adapters which will give me a bit more output. Then I think I have enough gain. A very silent setup. A bit more "forward" sounding than with Korg. Not as "forgiving" but I need to listen a lot more. But so far a very positive experience.
Then with 6 dB it is just enough. I will probably try out 12 dB later but for now I tried some Neutrik XLR to RCA adapters which will give me a bit more output. Then I think I have enough gain. A very silent setup. A bit more "forward" sounding than with Korg. Not as "forgiving" but I need to listen a lot more. But so far a very positive experience.
this one is certainly having different vibe to Korg B1
and it'll last forever
and it'll last forever
Now at least I have some spare parts for the amp. I like to order some extras.
What I learned was that if the BC 5XX transistors sits on these paper rails the leg spacing is very wide.
I will get some of the "normal" next time I need components. Maybe for other projects in the future the "wide" leg spacing types can be used or for some "experiments" at the "kitchen table".
What I learned was that if the BC 5XX transistors sits on these paper rails the leg spacing is very wide.
I will get some of the "normal" next time I need components. Maybe for other projects in the future the "wide" leg spacing types can be used or for some "experiments" at the "kitchen table".
Attachments
who cares for that?
I mean - I don't care - both flavors are perfectly fitting any TO92 pads alignment
I mean - I don't care - both flavors are perfectly fitting any TO92 pads alignment
OK! .....it is probably good enough then.......I have not actual tried to fit it into the PCB layout.
I had a spare BC 546A with same small leg spacing as in the kit.......which I used for the repair.
I wonder if I now have more BC5XX transistors than Mr. Pass. He only use FETs?
Piano sound is very nice. A bit more at the "crisp" side than Korg.
I had a spare BC 546A with same small leg spacing as in the kit.......which I used for the repair.
I wonder if I now have more BC5XX transistors than Mr. Pass. He only use FETs?
Piano sound is very nice. A bit more at the "crisp" side than Korg.
The wide leg spacing types fits perfect. They just "slides in" without need for any "legs adjustments".
PCB layout was made for those types.........but no problem at all with both types.
PCB layout was made for those types.........but no problem at all with both types.
Well, thanks for that. I bought one, but have yet to use it. Sort of like exercise equipment. There were no instructions, sort of self explanatory near as I can see. There are a couple videos that will clear it up. Will certainly save time and patience.I'm fairly certain, somewhere... I posted a very strong recommendation to purchase and use one of the Mega testers (or similar) when sorting parts.
I stand by that recommendation.
Everyone makes mistakes, but those little gizmos have saved me a great deal of time and effort. For this build as an example, I could not separate 556s from 546s without one.
Not selling my gadgets. We have "Prime Day" here through Amazon. My cart was full of cheap and cheerful gizmos. I still don't have my differential probe for my scope yet... but... a fella can dream. Now, I just do it the cheater's way and use two channels.
The writing on the 556 and 546 pieces was tiny, and not easy to see. With "helpers" and adjusting the angle of the tiny thing in the light, I could find an angle where the reflection off the face made it visible. I didnt think to use the little device!
Russellc
I always have multimeter standing by while soldering resistors. Most common mistake in packing and mis-sorting on my part. I still fall for the old chestnut, I dont have 750 R! Only .75K and so forth until brain klunksI think I still have a problem. I spend some time checking resistor values but not found anything wrong until now even that it can be difficult to see if a ring is red or brown. Then with some "in-circuit" measurement I could conclude the color.
I can adjust the rails to -+15 VDC with no problems but the M1/M2 gets too hot.
After 5 min or so I measured with heat-gun M1/M2 to 106 C which is too hot?
Is there a M1/M2 gate voltage I can check to see if it is wrong?
I can put heatsink on until I have found the error.........
Now......the M3 circuit I have not implemented because I do not implement the relays.
Is that the error......that it will reduce the load of M1/M2?
I measured all the resistors before they were mounted and wrote down their values so I used that instead of the color-rings but when it does not work as expected you need to look for the error. All resistors were ok but I swapped the two BD139/140 and this caused a BC546 to have 1.5 V as Vbe so CCS in +rail was 200 mA instead of 85. It was a "2-step" repair before it worked.......
Illuminated magnifier?The writing on the 556 and 546 pieces was tiny, and not easy to see. With "helpers" and adjusting the angle of the tiny thing in the light, I could find an angle where the reflection off the face made it visible.
I posted this awhile back... https://www.diyaudio.com/community/threads/diy-front-end-2022.394339/page-20#post-7265018
Without good lighting and magnification I would have to find a new line of work and a new hobby for sure...
Without good lighting and magnification I would have to find a new line of work and a new hobby for sure...
It is, but the battery is dead. It was just ambient light from overhead light. The little led would have helped, but writing is so faint it required tilting it around to get just the right reflection to reveal it.Illuminated magnifier?
Back from vacation... a nice box from Italy was in my home-office. ;-)
Look what we found during our trip...
https://www.rrpark.com/all-accommodations#cabooses
I think next time we'll stay here:
https://www.rrpark.com/accommodations/caboose-27
Look what we found during our trip...
https://www.rrpark.com/all-accommodations#cabooses
I think next time we'll stay here:
https://www.rrpark.com/accommodations/caboose-27
I am now convinced that 6dB gain is enough in my setup when output is taken from DAC XLR out.
I have implemented the SE version (the black box in first picture). I use short XLR to RCA cables between DAC and Iron-Pre.
Then 1m RCA cables from Iron-Pre to Lazy-Bush mono-blocks at the floor (last image).
I am also convinced that sound it "good enough" to go for the BAL version (if it will arrive some day at the DiyStore).
My plan is to build BAL version as mono blocks and place them close to Lazy-Bush mono blocks and utilize the BAL input and have long (1m) XLR cables from DAC to Iron-Pre.
I could even place the Lazy-Bush mono blocks just behind the speakers and then shorten my very long 1.5m speaker cables to e.g. 0.5m or shorter!
For critical listening my DAC in pre-amp mode the Vol-control is set to about 70% to 95% depending on how loud the recording is. So gain is about perfect.
Setup is even more silent than with Korg as preamp.
For BAL version I will go with steel chassis and yet a special order back panel from Gianluca.........
Good plan?
I have implemented the SE version (the black box in first picture). I use short XLR to RCA cables between DAC and Iron-Pre.
Then 1m RCA cables from Iron-Pre to Lazy-Bush mono-blocks at the floor (last image).
I am also convinced that sound it "good enough" to go for the BAL version (if it will arrive some day at the DiyStore).
My plan is to build BAL version as mono blocks and place them close to Lazy-Bush mono blocks and utilize the BAL input and have long (1m) XLR cables from DAC to Iron-Pre.
I could even place the Lazy-Bush mono blocks just behind the speakers and then shorten my very long 1.5m speaker cables to e.g. 0.5m or shorter!
For critical listening my DAC in pre-amp mode the Vol-control is set to about 70% to 95% depending on how loud the recording is. So gain is about perfect.
Setup is even more silent than with Korg as preamp.
For BAL version I will go with steel chassis and yet a special order back panel from Gianluca.........
Good plan?
Attachments
Gorgeous stuff!

Won't be tooooooooo long... Parts are still in short supplies and have gone up significantly in price.
Enjoy the tunes!
🥳
I am also convinced that sound it "good enough" to go for the BAL version (if it will arrive some day at the DiyStore).


Won't be tooooooooo long... Parts are still in short supplies and have gone up significantly in price.
Make sure you get the engineering pictures of the specific chassis you want... I know I bring it up often... but I goofed up. I did not ask about how the sides, top and bottom formed around each other for the chassis I ordered. I lost enough space on the back panel to not make my design work. It was no big deal, but I wish I had asked first....For BAL version I will go with steel chassis and yet a special order back panel from Gianluca.........
Good plan?
Enjoy the tunes!
🥳
😀heat-IR guns - most of them are simply stupid; only expensive ones certainly good
Brilliant!
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