B1 with Korg Triode

[Soundhappy]

Yes

 

[ml48]

Thanks.

 

[Soundhappy]

@ Ml48

The best simple solution is use transformer volume control with his rotary switch
in another separate box connected between audio source and B1 K preamp inputs.
Avoid mechanical vibrations of the Korg triodes for good sound quality

 

[DQ828]

Soundhappy


Thank you

 

[Pmat]

I posed this question a while back but never got an answer. My apologies regarding my newbieness. If I do two sets of parallel outputs so I can run a subwoofer do I need resistor between them? If so, what value and where?
Thanks,
Paul

 

[6L6]

The output is buffered. Just run it parallel.

 

[Pmat]

Thanks!

 

[ml48]

Soundhappy perhaps you or someone else can help me again. I've mislaid the 4 R1 resistors that came with the kit.What sort of value would they be or do I have to get new Q1 and Q2 from the store.

 

[ml48]

I have found 4 resistors with markings brown black black black brown.Are these likely to be the right resistors.Apologies for my dumbness.

 

[Soundhappy]

Soundhappy perhaps you or someone else can help me again. I've mislaid the 4 R1 resistors that came with the kit.What sort of value would they be or do I have to get new Q1 and Q2 from the store.

Just don't mix Q1 and Q2.
Q2 are jfets for CCS with his selected resistors.

Look at the build guide is step 44 and 45 B1 with Korg Nutube - diyAudio Guides

 

[ml48]

Soundhappy,thanks once again for your help.

 

[Soundhappy]

@ Ml48

Have a good time Enjoy

 

[Soundhappy]

The preamp I made for my son has come back to have a Trigger input connected which was always part of the plan but didn’t get done at the time.

My son was also hoping I could reduce the overall noise floor. When nothing is playing there are a variety of noises that the preamp emits from, a hiss, a steady tone, high pitched ringing etc! The noises stay the same even when there is no source connected. The noise variety changes depending where the volume is set, with the lowest volume setting having the loudest noise. The stepped attenuator I have cobbled together used good quality resistors.

If anyone has any thoughts on how I might go about reducing the noise floor I would be very glad to hear about it.

VinylSavor article >>Trouble Shooting Hum<< with step by step approach solutions VinylSavor: Technical guidelines

Edit: Article important information extract

 

[ml48]

I put in the R1 resistors that I found and thought might be correct (100 ohms) and when I switched on could smell burning and no light on the nutube.Seems like I found the wrong resistors.Where do I go from here.I may have damaged the Q1 and Q2s so can I get replacement Q1,2s and resistors.Any help appreciated.

 

[Soundhappy]

Could you show preamp inside on the photos ?
Edit: Jfets are available in stock https://www.mouser.co.uk/ProductDet...MI9ICu_v7A7QIV4R-tBh3xuwDzEAAYASAAEgLuufD_BwE

 

[ml48]

Rather not show inside because its a mess.Does 100 ohm for the R1 sound ok or is it way off because I'm guessing that that is where I've gone wrong.

 

[6L6]

If you can’t post photos it’s essentially impossible for us to help.

 

[SuppersReady]

I'd send the photos regardless. I've been successfully helped twice in this thread. Several pairs of eyes on a problem solves it so much quicker.

 

[DQ828]

VinylSavor article >>Trouble Shooting Hum<< with step by step approach solutions VinylSavor: Technical guidelines

Edit: Article important information extract

Thank you for the extra info, life's been too busy and I haven't been able to get back to it yet.

 

[LotsOHiFiFun]

Rather not show inside because its a mess.Does 100 ohm for the R1 sound ok or is it way off because I'm guessing that that is where I've gone wrong.

Please do post a photo.
Don't worry about the mess inside we just want to help so
you can enjoy great sound as soon as possible.
We'll throw you in the duck pond later!

I checked my values for R1 and in my case they are indeed 100 ohm
so it is very unlikely to be the cause of your woes. Disconnect the power supply from the main circuit board and check it is putting out the right voltage of around 24volts.

While you are doing this check you had the polarity (positive + and negative -) connected to the board correctly,
I think a few people have messed that up with similar results, but it was a long time back in the posts.

It that checks ok, then check each component for burns. It might be best to save time and start again.
Desolder everything, clean the board, check the tracks, sit
back have a rest and start again. Don't put anything back unless your sure it's ok and use the carpenters rule of check twice cut once.


Here's a pick of my board in case you want to check anything else.