[Jens]

Hi Morten,

My OLED display arrived safely today 

I hope to start installing it soon - however the new firmware seems not to be available yet. The Tortuga homepage says ** Will be available soon **. When is "soon"?

Jens

[tortugaranger]

Hi Morten,

My OLED display arrived safely today 

I hope to start installing it soon - however the new firmware seems not to be available yet. The Tortuga homepage says ** Will be available soon **. When is "soon"?

Jens

We had tested the firmware with new builds but then found some initialization issues when existing V25's were updated with the new firmware. Those problems were ironed out over the weekend. Doing some final checks this morning and if all goes well, the firmware will be posted on the website for download later today. 

[Jens]

We had tested the firmware with new builds but then found some initialization issues when existing V25's were updated with the new firmware. Those problems were ironed out over the weekend. Doing some final checks this morning and if all goes well, the firmware will be posted on the website for download later today. 

Hi Morten,

Always better to be safe than sorry - and much appreciated that you don't release until the worst 'kinks' are out

I just didn't want to start opening up my Tortuga until everything was ready and was slightly baffled because I was under the impression that the firmware was already released (I guess it may have been, didn't check till yesterday).

Just to be on the safe side, I will install the new firmware before doing anything else 

Jens
 

[tortugaranger]

I just didn't want to start opening up my Tortuga until everything was ready and was slightly baffled because I was under the impression that the firmware was already released (I guess it may have been, didn't check till yesterday).
Jens

We had released the firmware in new builds where we initialize new empty V25 boards with no existing firmware or stored history. That was going smoothly enough even though there are always a bunch of firmware improvements and bug fixes to be taken care of early on with any new release. Then we realized we'd overlooked a couple of key things that applied only when updating existing V25 boards that were not being initialized for the first time. That's now been resolved.

[tortugaranger]

The latest V25/OLED firmware has been posted for download and is applicable to all V25 boards regardless of display type.

https://www.tortugaaudio.com/support/product-documentation/?section=v25-firmware-updatesdownloads

[TheMonkey]

Hi all!

I think its a very nice upgrade to the new OLED screens! I ordered a screen about two weeks ago and it arrived the other day.
I have now installed it and loaded it up with the new firmware (rev209) and it worked straight away It's looking very nice!

However, I'm having one BIG problem    Please help!

Background noise/hiss. It's not there when switched off, dead silent like it should be.
When powered on it's either quite loud or quite silent. Whenever I enter the menu it's always a loud hiss. When going back to the volume control most of times it goes back to a small background noise (still a lot higher than with the 7 segment display), but sometimes the loud hiss stays and then it usually gets less intensive from adjusting the volume but not always.

Info about my setup:
   V25 in a balanced configuration (2 balanced in, 1 single ended in, 1 balanced out)
   Power amp with plenty of power (that's why even the quite silent hiss is bothering me)
   DAC with xlr

What I have tried so far:
   Disconnected all cables, plugged some back in, skipped the preamp - identifying the preamp as the cause of hiss.
   Factory Reset
   Power on power off
   Kill the power
   (Many) AutoCals (finishing without any problems, also making sure the preamps been on to stabilize temperature)
   Swapped LDRs

On some of the AutoCals the hiss started on one specific LDR (usually between steps 30-80). I did replace those specific LDRs but results are the same.
I don't think any of the LDRs are causing any problems (since it worked fine before), I think the screen/firmware is. When entering the menu the loud hiss always starts.
One more thing, the loud hiss is following the volume, well kind of at least.
First off, mute is not working, volume 1 is like a middle hiss, on volume 2 the hiss is loud and increasing between volume 2-60, between 60-100 the hiss is decreasing, on full volume the hiss is almost as low as on volume 1 (middle hiss.)

I'm not sure how to proceed. Any ideas?

Many thanks!
 / Simon

[tortugaranger]

Hi all!

I think its a very nice upgrade to the new OLED screens! I ordered a screen about two weeks ago and it arrived the other day.
I have now installed it and loaded it up with the new firmware (rev209) and it worked straight away It's looking very nice!

However, I'm having one BIG problem    Please help!

Background noise/hiss. It's not there when switched off, dead silent like it should be.
When powered on it's either quite loud or quite silent. Whenever I enter the menu it's always a loud hiss. When going back to the volume control most of times it goes back to a small background noise (still a lot higher than with the 7 segment display), but sometimes the loud hiss stays and then it usually gets less intensive from adjusting the volume but not always.

Info about my setup:
   V25 in a balanced configuration (2 balanced in, 1 single ended in, 1 balanced out)
   Power amp with plenty of power (that's why even the quite silent hiss is bothering me)
   DAC with xlr

What I have tried so far:
   Disconnected all cables, plugged some back in, skipped the preamp - identifying the preamp as the cause of hiss.
   Factory Reset
   Power on power off
   Kill the power
   (Many) AutoCals (finishing without any problems, also making sure the preamps been on to stabilize temperature)
   Swapped LDRs

On some of the AutoCals the hiss started on one specific LDR (usually between steps 30-80). I did replace those specific LDRs but results are the same.
I don't think any of the LDRs are causing any problems (since it worked fine before), I think the screen/firmware is. When entering the menu the loud hiss always starts.
One more thing, the loud hiss is following the volume, well kind of at least.
First off, mute is not working, volume 1 is like a middle hiss, on volume 2 the hiss is loud and increasing between volume 2-60, between 60-100 the hiss is decreasing, on full volume the hiss is almost as low as on volume 1 (middle hiss.)

I'm not sure how to proceed. Any ideas?

Many thanks!
 / Simon

I will give this some thought but 2 3 initial comments:

1) We have NEVER had ANY noise with the OLED display EVER during development or in our production preamps. By comparison the 7-segment display was noisy and we had to add suppression filters to eliminate it.

2) Since your preamp is a DIY unit I'd bet you all the beer you can drink in one evening that it's somehow related to grounding. Even more likely because yours is a balanced system.

3) Mute does work insofar as it mutes the audio signal volume but mute is unlikely to mute noise related to grounding.

[TheMonkey]

I will give this some thought but 2 3 initial comments:

1) We have NEVER had ANY noise with the OLED display EVER during development or in our production preamps. By comparison the 7-segment display was noisy and we had to add suppression filters to eliminate it.

2) Since your preamp is a DIY unit I'd bet you all the beer you can drink in one evening that it's somehow related to grounding. Even more likely because yours is a balanced system.

3) Mute does work insofar as it mutes the audio signal volume but mute is unlikely to mute noise related to grounding.

Thanks for your reply Morten! You are probably right about the grounding, I've been thinking the same it's just that I haven't changed much when it comes to the grounding.

Since I was going to upgrade to the new screen I thought I would skip the double outputs for a single ended in instead (for a phono stage).
I did this change before the OLED came and it was working fine but you are probably right about the grounding it's just that I don't find where the problem is.

I have now resoldered all the star-ground, all the solder for wires on the V25s and I have added extra wires to the 4th pin (chassis pin) on the XLRs for extra grounding as well. It is still the same.

However, I think I've narrowed it down. After doing a reset and then a CAL, the hiss is introduced when doing the "vref" on LDR 3.
Does that tell you where the problem/bad grounding is?

Thanks!
 / Simon

[tortugaranger]

Thanks for your reply Morten! You are probably right about the grounding, I've been thinking the same it's just that I haven't changed much when it comes to the grounding.

Since I was going to upgrade to the new screen I thought I would skip the double outputs for a single ended in instead (for a phono stage).
I did this change before the OLED came and it was working fine but you are probably right about the grounding it's just that I don't find where the problem is.

I have now resoldered all the star-ground, all the solder for wires on the V25s and I have added extra wires to the 4th pin (chassis pin) on the XLRs for extra grounding as well. It is still the same.

However, I think I've narrowed it down. After doing a reset and then a CAL, the hiss is introduced when doing the "vref" on LDR 3.
Does that tell you where the problem/bad grounding is?

Thanks!
 / Simon

I recommend you NOT have your amps turned on or have any interconnects connected to the preamp at all when running calibration until you've resolved the noise problem during normal volume control operation. Whatever the root cause of the noise it's highly unlikely to have anything to do with calibration or the primary LDRs themselves. Doing resets isn't going to help either since all that really does is empty out the calibration tables, reinitialize a few variables and chew up your time. Once you've run cal 1-2 times with the preamp isolated at the default #1/20k setting, only then reconnect you ICs and turn amps on etc.

I also recommend you review the recommended balanced wiring section within the online kit assembly instructions that can be found here:  https://www.tortugaaudio.com/support/product-documentation/?section=kit-assembly-instructions-oled  I realize you had it all working before without any noise which makes diagnosing this challenging. I'm at a loss to explain any hissing related to the OLED display since we have literally never had any noise problems with the OLED display installed. That is not to say your hiss/noise isn't real, only that we have zero history diagnosing/resolving OLED related noise.

With everything hooked up,  powered up, turned on and with noise present I suggest you do the following. First disconnect the encoder from the OLED display module and note any change, next disconnect the smaller 2x5 pin cable from the V25.J3 header and note any change - this cable is only for conveying the encoder signals and the IR receiver signals to the V25 board. Last but not least pull the 2x7 cable from the V25.J9 header which disconnects the OLED control/data signals completely.

I had one DIY customer with balanced system connected to old existing 3rd party preamp tube buffer. He had  hum hum and more hum which was eventually traced to a ground loop caused by the tube preamp circuit board. After cutting a trace on both channels of the tube buffer PCB the hum totally disappeard. Took weeks to diagnose and resolve. Noise/hum can be very challenging.

[glynnw]

Morten - Can you post a picture of the new OLED display as it will display when the signal is sent to either channel through use of the balance control.  In my older one I get a digital readout of each channel all the time and it is easy for me to see how the balance is adjusted.  Let's say the old method would display   44 41.  What would this look like on the new OLED?

[tortugaranger]

Morten - Can you post a picture of the new OLED display as it will display when the signal is sent to either channel through use of the balance control.  In my older one I get a digital readout of each channel all the time and it is easy for me to see how the balance is adjusted.  Let's say the old method would display   44 41.  What would this look like on the new OLED?

This example shows the nominal volume at step 41 but the channel balance is shifted +4 steps to the right. If the balance were shifted left the "4" would be on the left side of the display. For the V25 that's 4 steps at ~0.6 dB per step. When channel balance is neutral the balance number (zero) is not visible. Max channel balance steps is 20 left or right (12 dB).

In order to maintain overall actual volume level as the channel balance shifts left or right what happens under the hood is for every other step (an even step), the opposite channel will go down one. Hence channel balance is actually a channel volume difference at a given average volume level. To illustrate, see the following table for the +4 case

Master volume - 41

Balance Adjustment     Left Vol      Right Vol
             0                     41              41
             +1R                 41              42
             +2R                 40              42
             +3R                 40              43
             +4R                 39              43