Nobelium - tube bass preamp project

[matmonster58]

I'm waiting to get the right XLR jacks but I'll do some testing in the mean time.

What's a good software for measuring frequency response and THD?

I have REW and Multitone analyser but I haven't used them before.

 

[vigilante398]

What's a good software for measuring frequency response and THD?

I have REW and Multitone analyser but I haven't used them before.

REW is what I used when I was developing the spec for the Unagi E4305 and testing prototypes, but that was a while ago and I haven't used it since.

 

[SamuelG]

I've been in this same situation for the past few months.
Short answer: You can't get them right now

I've talked to Jensen, radial, and every other distributor and no one has them. I even talked to Jack from Nobel and he's having a hard time getting a hold of them. There is a Rode branded one on reverb in Australia right now but I haven't been able to get in contact with the seller.

What I ended up doing was just waiting until I found a JDI that was cheap enough and then I pulled the transformer out of it.
With how hard they are to find, I just wouldn't offer a Jensen transformer as an option. Cinemag, Unagi, and LBA are all great alternatives.

I ended up getting that RODE branded one and took on the project.
I have some Jensen’s on back, back, back order with a hope and a prayer that they come sometime this year. I want to make the most of the time it’s taken to design my UV print and find the parts
I’m really keen to see how the trannies compare - in circuit - with proper analysis

 

[matmonster58]

From my initial listening:

Unagi - Amazing, sounds very clear and balanced throughout the whole frequency range. I would choose the Unagi if you want a natural well extended sound

LBA - Also amazing but more colored. I hear a touch more heft in the low end and the highs are tucked down just a bit. Together you get a fatter, smoother tone.

Both the unagi and LBA give what I'm looking for in a "tubey" tone in the high end. I don't have a better way to describe it than that.

Jensen - The Jensen has a more "polite" tone. The lows and highs don't extend as much and the "tubey" character gets smoothed over a bit. I guess I would describe the Jensen as being true neutral, whereas the Unagi and LBA feel like they are enhancing your tone.

 

[Tassieviking]

I'm waiting to get the right XLR jacks but I'll do some testing in the mean time.

If you remove the nuts and washers from the switch on the XLR PCB it will be easier to align the switch with the slot on the enclosure.

 

[TillMack]

From my initial listening:

Unagi - Amazing, sounds very clear and balanced throughout the whole frequency range. I would choose the Unagi if you want a natural well extended sound

LBA - Also amazing but more colored. I hear a touch more heft in the low end and the highs are tucked down just a bit. Together you get a fatter, smoother tone.

Both the unagi and LBA give what I'm looking for in a "tubey" tone in the high end. I don't have a better way to describe it than that.

Jensen - The Jensen has a more "polite" tone. The lows and highs don't extend as much and the "tubey" character gets smoothed over a bit. I guess I would describe the Jensen as being true neutral, whereas the Unagi and LBA feel like they are enhancing your tone.

Thanks for the comparison.
You made me decide to go with the Unagi transformer for my build.
Ordered everything.
I will use the Neutrik NC3 MAV as XLR Output, looks promising from the datasheet measurements and maybe it's an option for everyone like me, cause in Europe it's hard to get the Amphenol.

 

[Tassieviking]

From my initial listening:

Unagi - Amazing, sounds very clear and balanced throughout the whole frequency range. I would choose the Unagi if you want a natural well extended sound

LBA - Also amazing but more colored. I hear a touch more heft in the low end and the highs are tucked down just a bit. Together you get a fatter, smoother tone.

Both the unagi and LBA give what I'm looking for in a "tubey" tone in the high end. I don't have a better way to describe it than that.

Jensen - The Jensen has a more "polite" tone. The lows and highs don't extend as much and the "tubey" character gets smoothed over a bit. I guess I would describe the Jensen as being true neutral, whereas the Unagi and LBA feel like they are enhancing your tone.

I think that Mr Sushi "Nathan" Box should borrow this post and the audio files for the C2CE website on the Unagi E-4305 page, and also on the Steddi Go and Nobelium pages as well to help people work out what transformer they want to use.
Well done young fellah. ( Unless the 58 is your birth year then make it old fart instead cause you would be 2 years older then me )

Cheers
Mick

EDIT: I might as well be the one that starts the "magic tone is in..." rumor, the reason that the LBA transformer sounds more colorful is because the purple PCB enhances and colors the sound more.
From now on the purple PCB's are going to be a collectors item because of those magic purple colors bleach through to the sound quality.

( I spelled colour wrong to help the overseas people understand better, it's colours not colors, you guys have to stop loosing things over there)

 

[matmonster58]

Those clips were done looping the bass with an Hx Stomp. The Nobelium was set with no hpf, bass maxed, treble at noon, and xlr volume maxed. I was hitting the transformers as hard as I could so that the differences would be more pronounced.

I haven't gotten a chance to compare with more neutral settings. The differences may be very subtle once you back the bass and volume off.