Erin and Greg.
I found that when at 5V and 3.3V, that the standing current had reduced markedly. A 1.5mA ( or thereabouts) constant current diode would also improve MEASURED performance over a wider current range.However, the AUDIBLE improvement at 5V may be barely noticeable.
If you measure the voltage across the 33R which governs standby current, you will see that the available modulation current has decreased quite a bit at low voltages. Greg, your PCB design is fine at >1A with the CL bypassed.
Alex
I found that when at 5V and 3.3V, that the standing current had reduced markedly. A 1.5mA ( or thereabouts) constant current diode would also improve MEASURED performance over a wider current range.However, the AUDIBLE improvement at 5V may be barely noticeable.
If you measure the voltage across the 33R which governs standby current, you will see that the available modulation current has decreased quite a bit at low voltages. Greg, your PCB design is fine at >1A with the CL bypassed.
Alex
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Hi Greg,
I'm not using the current limiter. The power supply i'm using is one I made when I was at TAFE learning electronics. It has adjustable voltage and a 100ma or 1A switchable option. On 1A the Touch runs fine, as long as only using the network to play music. (no USB devices connected) I have left it running through the JLH for weeks on end with no ill effects.
You really must try the JLH on the Touch and let me know what you think.
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Hi Erin,
I thought I had all the bits so I just threw one together, but...... failure, 5v with no load but as soon as I plug the PSU into the SB Touch the voltage drops to 4.5v so the SBT will not boot.
I will look for another option on the weekend. I might have to read sandyK's post a bit more closely.
Regards
I suspect you may have a dry joint or wrong value if you were too quick with the build.
Hi Greg
Have you a bench PSU to hook the new JLH up to ?
It may just be that the large electros need time to form.
There can be quite heavy currents drawn early in the peace, especially if using 2 x 4,700uF which are recommended for higher current versions without a CL stage.
I would also check the main JLH voltages, especially the just under 1.8V of the 3 transistor VBEs in series, (junction of the 120K and the BC639 base.)
and close to 600mV across the 33ohm. Keep an eye on the 2SC5171 temperatures at this stage too, and more so if using the2 x parallel 4,700uF.
Alex
Have you a bench PSU to hook the new JLH up to ?
It may just be that the large electros need time to form.
There can be quite heavy currents drawn early in the peace, especially if using 2 x 4,700uF which are recommended for higher current versions without a CL stage.
I would also check the main JLH voltages, especially the just under 1.8V of the 3 transistor VBEs in series, (junction of the 120K and the BC639 base.)
and close to 600mV across the 33ohm. Keep an eye on the 2SC5171 temperatures at this stage too, and more so if using the2 x parallel 4,700uF.
Alex
Hi Erin,
Oh no, no, no, I don't do dry joints or wrong values.
But I do use 5v supplies with current limiting resistors...oooooops.
EDIT: I also short out limiting resistors, forgetting why they were there in the first place. Ouch!
Regards
Hi Erin,
Oh no, no, no, I don't do dry joints or wrong values.
Sorry for that, I wasn't insinuating anything Greg.
Just trying to help.So, how does it sound?
Sorry for that, I wasn't insinuating anything Greg.
So, how does it sound?
Hi Erin,
I understand, no offense taken. I have been soldering for over 40 years and reached expert level many decades ago. Plus, being a little bit anal about things I inspect while cleaning every solder joint I ever do.
That resistor I was talking about a few posts ago was there to limit the current because there is 15 volts going into the 5 volt regulator. When I shorted the current limiting resistor the 5 volt regulator got very hot very quickly
(obviously).I bought a 6 volt transformer yesterday and was able to compare my basic PSU with JLH ripple eater (standard values) to the standard switchmode PSU. After many swappings back and forth, I can say I perceived there was a small but noticeable improvement. It is worth doing a proper 5V PSU and seeing what benefit the JLH ripple eater provides. I think it would also be worthwhile doing sandyK's mods to the JLH to see the benefits.
I should mention that the PSU comparisons where done using the digital out of the SBT. I must test the analog outs, one would assume the differences between PSUs to be greater.
regards
Hi Greg. I use a TDA1541 non oversampling DAC with a valve output stage. It uses a CS8414 digital receiver. This sort of DAC is sensitive to jitter. What I have found is that the better the source that I feed it with, the better it sounds.
I'm glad to hear that you observed an improvement in sound. This is in line with what most people say about adding an improved power supply to the squeezebox.
Always using SPDIF, I tried the SMPS with the touch and found it to sound rather average. I then tried a linear power supply, and found it sounded much better.
When I added the JLH ripple eater there was another leap in sound quality.
There is an interesting discussion about Linn transports vs Squeezbox on this forum between non-modding guys. Linn Sneaky vs Sonos
Some notice little difference between Linn and Squeezbox and others think there was a big difference. But one thing in common is that it appears that none of them had upgraded the power supply on a Squeezbox.
Not that I am saying that Linn is the best transport going around, but I think that the squeezebox with a good power supply would come very close at less than 1/20th price.
I'm glad to hear that you observed an improvement in sound. This is in line with what most people say about adding an improved power supply to the squeezebox.
Always using SPDIF, I tried the SMPS with the touch and found it to sound rather average. I then tried a linear power supply, and found it sounded much better.
When I added the JLH ripple eater there was another leap in sound quality.
There is an interesting discussion about Linn transports vs Squeezbox on this forum between non-modding guys. Linn Sneaky vs Sonos
Some notice little difference between Linn and Squeezbox and others think there was a big difference. But one thing in common is that it appears that none of them had upgraded the power supply on a Squeezbox.
Not that I am saying that Linn is the best transport going around, but I think that the squeezebox with a good power supply would come very close at less than 1/20th price.
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