spacemishka
Member
i have seen it, but how do i know whether a capacitor is a film capacitor or not....
U47xfet PCB from UTM / IGS?
- Thread starter TimG
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Volume11
Well-known member
I'm just referencing the pcb to see which are polarized or not, and also checking some of the photos at the beginning of this thread. There's 3 styrene caps, one should've came with the kit, the other two I ordered from Banzai, along with the 2sk117.
| SKU21152 | Styroflex 100pF | |||
| SKU27397 | 2SK117 |
Volume11
Well-known member
Is C10 a standard electrolytic cap? I'm not sure what "Elna" means, maybe the brand?
Elna is indeed a capacitor manufacturer. The "pattern" in the BOM file says "CE" for it, which most likely stands for "Capacitor, Electrolytic". Not that the round footprint isn't a dead giveaway anyway...
https://utmindustry.com/wp-content/uploads/2023/03/original_1675763445UTM47LB_PCB-570x855.jpg
spacemishka
Member
i got it about CE but C1M400 like C4 and C9 look like Polyester-Caps in this picture
https://groupdiy.com/threads/u47xfet-pcb-from-utm-igs.82882/post-1073051
Volume11
Well-known member
Ok, I figured that I should double check just in case. Thanks
spacemishka
Member
another question to the parts list 
which variant of the BC550 and BC560 is recommended. And the C4 (0.1/100)is which "unit" uF or pF?
which variant of the BC550 and BC560 is recommended. And the C4 (0.1/100)is which "unit" uF or pF?
0.1/100 = 0.1uF (100nF) rated at 100v
spacemishka
Member
thank you
Volume11
Well-known member
Are you guys using the cheesy shock mount that came with the mic body, or did you find an upgrade of some sort?
I'm going to give this build a go and have ordered a UTM47LB kit and a UTM0547f transformer from UTM.
The hardest part is deciphering the BOM and sourcing the components. Its like trying to solving the da Vinci code.
Doesn't help when TimGs Mouser BOM is only 50% complete.
Anyway I got the Mouser BOM and hunting down the rest. Nothing like the thrill of the hunt.
The only thing I have to go off is the schematics and the build picture which are a bit ambiguous.
I sent Igor from UTM an email asking him for clarification of some of the caps used as there has been some confusion as to what type they were.
This is what he said.
C2, C3 - styroflex or ceramic
C4, C9 - WIMA or similar
C6 - Tantal (0.33uF)
C2, C3 I think I can get 18p and 33p Polystyrene caps, just waiting on conformation on stock. If not Ceramics it is.
C4, C9 WIMA caps are easy to get but I might go MKTs.
C6 He said tantalum but I can only get them in 35V. Would they work? If not an Electrolytic it is.
C10 Elna caps are high quality Japanese caps and are easy to get. Should use them for all Electrolytics.
Anyway I hope I've got things right.
The hardest part is deciphering the BOM and sourcing the components. Its like trying to solving the da Vinci code.
Doesn't help when TimGs Mouser BOM is only 50% complete.
Anyway I got the Mouser BOM and hunting down the rest. Nothing like the thrill of the hunt.
The only thing I have to go off is the schematics and the build picture which are a bit ambiguous.
I sent Igor from UTM an email asking him for clarification of some of the caps used as there has been some confusion as to what type they were.
This is what he said.
C2, C3 - styroflex or ceramic
C4, C9 - WIMA or similar
C6 - Tantal (0.33uF)
C2, C3 I think I can get 18p and 33p Polystyrene caps, just waiting on conformation on stock. If not Ceramics it is.
C4, C9 WIMA caps are easy to get but I might go MKTs.
C6 He said tantalum but I can only get them in 35V. Would they work? If not an Electrolytic it is.
C10 Elna caps are high quality Japanese caps and are easy to get. Should use them for all Electrolytics.
Anyway I hope I've got things right.
I'm going to give this build a go and have ordered a UTM47LB kit and a UTM0547f transformer from UTM.
The hardest part is deciphering the BOM and sourcing the components. Its like trying to solving the da Vinci code.
Doesn't help when TimGs Mouser BOM is only 50% complete.
Anyway I got the Mouser BOM and hunting down the rest. Nothing like the thrill of the hunt.
The only thing I have to go off is the schematics and the build picture which are a bit ambiguous.
I sent Igor from UTM an email asking him for clarification of some of the caps used as there has been some confusion as to what type they were.
This is what he said.
C2, C3 - styroflex or ceramic
C4, C9 - WIMA or similar
C6 - Tantal (0.33uF)
C2, C3 I think I can get 18p and 33p Polystyrene caps, just waiting on conformation on stock. If not Ceramics it is.
C6 He said tantalum but I can only get them in 35V. Would they work? If not an Electrolytic it is.
What's similar to a WIMA cap?
C10 Elna caps are high quality Japanese caps and are easy to get. Should use them for all Electrolytics.
Anyway I hope I've got things right.
The hardest part is deciphering the BOM and sourcing the components. Its like trying to solving the da Vinci code.
Doesn't help when TimGs Mouser BOM is only 50% complete.
Anyway I got the Mouser BOM and hunting down the rest. Nothing like the thrill of the hunt.
The only thing I have to go off is the schematics and the build picture which are a bit ambiguous.
I sent Igor from UTM an email asking him for clarification of some of the caps used as there has been some confusion as to what type they were.
This is what he said.
C2, C3 - styroflex or ceramic
C4, C9 - WIMA or similar
C6 - Tantal (0.33uF)
C2, C3 I think I can get 18p and 33p Polystyrene caps, just waiting on conformation on stock. If not Ceramics it is.
C6 He said tantalum but I can only get them in 35V. Would they work? If not an Electrolytic it is.
What's similar to a WIMA cap?
C10 Elna caps are high quality Japanese caps and are easy to get. Should use them for all Electrolytics.
Anyway I hope I've got things right.
Aim for C0G / NP0 - values so low will more likely than not be those materials by default, but you'll wanna make sure.
I'd stick with known-brand Japanese electrolytics - Panasonic, Nichicon, Rubycon, Elna, United Chemi-Con.
See above.
Film capacitors (PET, PP) - you'll be hard-pressed to hear any differences between the same value but different materials. Well, outside of deluding yourself, that is...
Volume11
Well-known member
Are you guys using 550 and 560 "B" or "C" transistors? I read that the C have a higher gain rating. Not sure if this is a good thing or bad. Thanks!
I used BC550B and BC560B with hfe between 300..400 in similar schemes. They are closer to BC182B and BC212B from the original scheme. I paired T5 and T6.
Attachments
Volume11
Well-known member
Awesome, thank you so much!
Finally finished this build.
Went for the Flat K47 from Arienne Audio. Excellent capsule.
Wouldn't fit in a 103 shell. Its about 5mm to long. I couldn't see any other way of mounting the transformer.
I put it in a 47 shell from AliExpress.
https://www.aliexpress.com/item/100....order_list.order_list_main.23.26381802Jz7qwo
There are cheaper ones of this there which look the same.
Had to cut back the 2 small ridges with side cutters so it would fit in.
Looks good and sounds great.
Used the B version of BC550/560 but if I do another ill use the C as it could do with a more gain if the C will do that.
Went for the Flat K47 from Arienne Audio. Excellent capsule.
Wouldn't fit in a 103 shell. Its about 5mm to long. I couldn't see any other way of mounting the transformer.
I put it in a 47 shell from AliExpress.
https://www.aliexpress.com/item/100....order_list.order_list_main.23.26381802Jz7qwo
There are cheaper ones of this there which look the same.
Had to cut back the 2 small ridges with side cutters so it would fit in.
Looks good and sounds great.
Used the B version of BC550/560 but if I do another ill use the C as it could do with a more gain if the C will do that.
Attachments
Hi @Plonker !
Many Congratulations!
You managed to complete a nice project!
Maybe you can post some sound tests.
Have you matched the hfe for the BC550/560 final complementary transistors? What value do they have?
*It is possible that using version C with too high hfe will cause autoscillations, become unstable. Not getting enough output level?
