i don't know whether the NuTube filament has polarity, but regular tube filaments have no polarity, and can take AC or DC.
Looking at the spec sheet it looks like the NuTube filament does not have polarity:
https://korgnutube.com/en/guide/
Looking at the spec sheet it looks like the NuTube filament does not have polarity:
https://korgnutube.com/en/guide/
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When you have polenta of dollars nice hardware swapping leads feel iffy but the test card volunteered and guess what, sometimes we only need to let go of pride and stubbornness.
It was magic, it runs with reversed polarity or as some refer to it “correct polarity”
thankfully for the soldering inspection, it is the sad side story that landed me in this, the real build was ready for trial run when I realised that my mirrored powers switch looked over engineered, flicked the switch and lit up the amp and fried the diod.
progressively did the re-soldering go from bad to worse, realised that the soldering iron was packing in, so correctly spotted some components have been hammered there with a cold iron. 🙂
so I cloud have save 2 days of hardship if I would have spotted the bad soldering iron and accepted that amps that glow do not need fixing, as the actual works.
So that is how you don’t build a amp.
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Akshually...
I know I've made similar mistakes and will make them again. So maybe this really is how one builds an amp? 🙂
Glad you got it sorted!
Hi guys, There was some chat the other week about how to fit the Cornell D caps as per Claud's suggestion onto the board, especially the large cap. Well just finished my soldering of my input selector, so I could complete the thing fully wired, so i though I would show befor I fully case it up.
Yes the large caps are a difficult fit & I had adhered them to the board with JB Weld (very strong but messy, messy adhesive. Under the caps are two foam pad to prevent vibration.
V/C is a Muses by Audio Academy, which has of course vol, but more importantly balance as well. Seems to work smoothly & does not upset the Korgs.
How does it sound well great on my 2nd workshop rig, but the test is when I get it into my main system & compare it so my 1st B1-K, which I have rigged up with a Khomo 64 click passive pre to control the vol. Will report more later
The 3rd photo is of my Studer 900 dual supply P/S, really great quiet supply I am surprised more people do not use, cheap as chips from F/bay.
cheers
Yes the large caps are a difficult fit & I had adhered them to the board with JB Weld (very strong but messy, messy adhesive. Under the caps are two foam pad to prevent vibration.
V/C is a Muses by Audio Academy, which has of course vol, but more importantly balance as well. Seems to work smoothly & does not upset the Korgs.
How does it sound well great on my 2nd workshop rig, but the test is when I get it into my main system & compare it so my 1st B1-K, which I have rigged up with a Khomo 64 click passive pre to control the vol. Will report more later
The 3rd photo is of my Studer 900 dual supply P/S, really great quiet supply I am surprised more people do not use, cheap as chips from F/bay.
cheers
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Anyone put in the MUSES volume control from Academy Audio in the stock DIYaudiostore chassis?
https://www.academyaudio.com/produc...es-micro-volume-control-board-low-noise-power
Was thinking of trying to fit the VCU as well as the LPS9 in the stock chassis. Wondering if it will be a bit fit in the chassis.
https://www.academyaudio.com/produc...es-micro-volume-control-board-low-noise-power
Was thinking of trying to fit the VCU as well as the LPS9 in the stock chassis. Wondering if it will be a bit fit in the chassis.
Ignore the above ^^^
Realizing now that there is definitely no space inside the stock store chassis for two new PCBS! Especially if upgrading the signal caps to big film ones!
Realizing now that there is definitely no space inside the stock store chassis for two new PCBS! Especially if upgrading the signal caps to big film ones!
Hi, well if you want to upgrade your unit, I would not use the enclosure supplied from the store, My one cost about $60-00 from F/bay, but also have found that is normally cheaper & faster postage shopping through Aliepress
https://www.aliexpress.com/item/400...1;26.92;-1;-1@salePrice;NZD;search-mainSearch
Cheers
https://www.aliexpress.com/item/400...1;26.92;-1;-1@salePrice;NZD;search-mainSearch
Cheers
Well, back in the 80s I applied power to a board, 5, 12 and 69 VDC. The 69 were current limited to 3A.
As you can imagine, manufacturing had made an error and did not key the connectors. I had used this board several times before selling it off. The last attempt before sell off, I was tired and I swapped the 5 and 69 VDC connectors.
5V, 1/4 watt diodes GLOW with white heat, in my case about a jet of white heat, when you put 69 VDC @ 3A backwards.
I blew more than a quarter of a mil, and that was in the early 80s. But I was absolved and manufacturing was told to NOT do that again, ever!
After that even, I decided that software is more fun. Have you ever driven a "large vibration test shaker table" with the Rolling Stones (*) as input signal? The entire building shook with nodes we didn't know it had.
(*) Used my Walkman playing Sympathy for the Devil as the test signal in the shaker ampl controller. It ran a DC and low pass filter. What was really funny is that normally you use steady narrow signal that have no time domain changes... but a song changes with time... so we were really resonating the entire building since the isolating springs for the shaker were tuned for a few narrow frequencies. It was AWESOME.
Got my kit today, a few questions...
1. In regards to the x8 1000uF 25V caps, have people been increasing the capacitance on these for more filtering? I don't see how this would hurt, especially if one can select a part with the same PCB form factor. Also 25V also seems rather low, more so on that first cap that sees 24V directly from the PSU...
2. I notice the supplied DC jack is not isolated from the chassis meaning the - (ground) connects right to the chassis. I now realize this serves as the chassis ground connection for the circuit. Has anyone tried using an isolated PSU jack and floating the circuit?
3. What are people using for standoffs to help with isolation and tube microphonics? I saw some discussion way back in this thread about rubber standoffs ("3M automotive sound deadening standoffs") but the product seems to no longer be available.
Kinda bummed I got all standard 1/4W blue metal film resistors (except x4 1K 1/8W metal films), thought the kit came with the nicer resistors shown in the build guide. That's ok, I replace/upgrade some of these.
Thanks!
1. In regards to the x8 1000uF 25V caps, have people been increasing the capacitance on these for more filtering? I don't see how this would hurt, especially if one can select a part with the same PCB form factor. Also 25V also seems rather low, more so on that first cap that sees 24V directly from the PSU...
2. I notice the supplied DC jack is not isolated from the chassis meaning the - (ground) connects right to the chassis. I now realize this serves as the chassis ground connection for the circuit. Has anyone tried using an isolated PSU jack and floating the circuit?
3. What are people using for standoffs to help with isolation and tube microphonics? I saw some discussion way back in this thread about rubber standoffs ("3M automotive sound deadening standoffs") but the product seems to no longer be available.
Kinda bummed I got all standard 1/4W blue metal film resistors (except x4 1K 1/8W metal films), thought the kit came with the nicer resistors shown in the build guide. That's ok, I replace/upgrade some of these.
Thanks!
Yes, a lot of people have increased the size of the filter caps. Here is an example. Good luck!
https://www.diyaudio.com/community/threads/b1-with-korg-triode.313612/page-127#post-5826133
The marked locations seem to allow for a 14mm cap with 7mm lead spacing. I wouldn't worry about increasing the voltage of the caps. Just use good caps otherwise the size will get out of hand.
https://www.diyaudio.com/community/threads/b1-with-korg-triode.313612/page-127#post-5826133
The marked locations seem to allow for a 14mm cap with 7mm lead spacing. I wouldn't worry about increasing the voltage of the caps. Just use good caps otherwise the size will get out of hand.
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I am going to give these guys a shot on the three filter caps coming right off of the power supply.
UKT1E332MHD
https://www.mouser.com/ProductDetail/647-UKT1E332MHD
UKT1E332MHD
https://www.mouser.com/ProductDetail/647-UKT1E332MHD
Interesting
That post talks about upgrading 3 PI filter caps, isn't there 4? I see four looking at the PS rail in the schematic.
There are 4 but as posted back then given 3 made little difference I didn't bother about the last one downstream, eventhough Fc is indeed different... but for HF I have the SMPS filter anyway, so I addressed this in another way .
Mostly, that was ages ago and I wasn't sure (no one was really if I remember) at that time that the SMPS would start on a regular basis with the already massively increased C value!
There is more to gain elsewhere IMHO...
All IME
Claude
Mostly, that was ages ago and I wasn't sure (no one was really if I remember) at that time that the SMPS would start on a regular basis with the already massively increased C value!
There is more to gain elsewhere IMHO...
All IME
Claude
ChrisM91, I used these to mount the board -
I also used Pete Millett's NuTube mount and have had zero microphonic issues.
Installed slightly larger PS caps with a little effort. Photos a few pages back.
iFlight 12PCS M3X7+4.5 Anti-Vibration Fixed Screws Mounting Hardware Spacer Standoff RC Screws kit with 12PCS M3 Nylon Hex Nut for Naze32 CC3D F3 F4 Flight Controller FPV Racer -
Still in stock on the site that will not be named.I also used Pete Millett's NuTube mount and have had zero microphonic issues.
Installed slightly larger PS caps with a little effort. Photos a few pages back.