My Blind Test Results

[solderdude]

For comparative measurements it isn't such a big problem.
Still.. to get a 0.1dB accuracy you need 1% accuracy.... on both channels, under actual load.
When one is looking for a cheap meter and want to do some low voltage AC measurements over a wide audio range the suggested meter is all one needs and is rather cheap.

 

[voodooless]

Would a 'not so good' meter give different measurements? Not in absolute numbers, but for comparison?
What I mean: even if 4 V are detected as 3 V by the Multimeter, this would be reproducible using this item and so not inflict to OP's attempt to objectivity?

There is still this:

 

[Salt]

So, let's say, if one is 2,020 V and the other is 2,012 V, this would match sufficiently?

 

[solderdude]

That would certainly be good enough... under actual load on both channels with a decent meter.
A cheap meter with 200VAC setting, however can never show that. It would read around 1.5V in both cases.

 

[MoreExpensiveSuchBetter]

Hello again all!

Sorry for the late reply, I ended up ordering an AN8008 so it took some time to get here. Here is what I did:

1. Set it to measure HZ - sent a sine wave from REW at 60hz

2. Checked the frequency of both amps and confirmed they showed 60hz.

3. Switched AN8008 to measure AC V

4. Matched the voltage within .001. I believe one went up and down by .001. In this case they were both at .098.

5. Performed blind test with the Douk Little Bear and partner changing.

My results were pretty much similar as the first go around. This time I did 15 songs with longer breaks between. I picked the L30 for 4 of them - so a bit more than last time! My notes were similar in that the dynamics appeared to be better on the SPL and there was ever so slightly a bit more top end and less bloated bass. I find on the SPL it is easier for me to hear compression characteristics and other elements better. I’m trying to be very careful with my wording here to not come across as an audiophile.

I am still not convinced - from everything I’ve read here it should sound identical or if anything the Topping L30 should sound better - unless I am liking flaws or something along those lines. At this point, do you have any other insight? Perhaps it has to do with the impedance? I also used the stock probes on the multimeter, should I maybe pickup some of those alligator clamp ones for better results?

Thanks again to all - this has been an awesome experiment,

 

[kemmler3D]

Hello again all!

Sorry for the late reply, I ended up ordering an AN8008 so it took some time to get here. Here is what I did:

1. Set it to measure HZ - sent a sine wave from REW at 60hz

2. Checked the frequency of both amps and confirmed they showed 60hz.

3. Switched AN8008 to measure AC V

4. Matched the voltage within .001. I believe one went up and down by .001. In this case they were both at .098.

5. Performed blind test with the Douk Little Bear and partner changing.

My results were pretty much similar as the first go around. This time I did 15 songs with longer breaks between. I picked the L30 for 4 of them - so a bit more than last time! My notes were similar in that the dynamics appeared to be better on the SPL and there was ever so slightly a bit more top end and less bloated bass. I find on the SPL it is easier for me to hear compression characteristics and other elements better. I’m trying to be very careful with my wording here to not come across as an audiophile.

I am still not convinced - from everything I’ve read here it should sound identical or if anything the Topping L30 should sound better - unless I am liking flaws or something along those lines. At this point, do you have any other insight? Perhaps it has to do with the impedance? I also used the stock probes on the multimeter, should I maybe pickup some of those alligator clamp ones for better results?

Thanks again to all - this has been an awesome experiment,

First of all, much respect for going to the trouble of level matching properly, etc. I gather that this needs to be done with the headphones connected, but assuming you did that, I personally have no further notes on method.

Based on the graph posted earlier I guess it's possible you're hearing a bit of distortion, especially if you're listening loud. In that case, you might be "liking flaws".

When it comes to (a little bit of) distortion this is actually super common. People DO generally enjoy a bit of harmonic distortion - I can tell you it's actually pretty rare not to add any harmonic distortion during the production of a record if you're starting with super clean sounds... I mean, look at the entire world of guitar tones and you'll see what I mean. So when a piece of gear (like a tube amp, or maybe this amp) adds a little more... sometimes it sounds good.

So if you were hearing a little extra THD and you liked it... that's not a surprise, nor is there anything wrong with that per se, it just goes against the philosophy of high fidelity a bit, but if you like the sound, hey, it's your setup.

 

[voodooless]

@MoreExpensiveSuchBetter, thanks for stepping up and improving your method!

Do we have any objective data on the SPL Phonitor 2? I suspect performance will be similar to the version tested at ASR, and that it does not like the low impedance headphones.

 

[MoreExpensiveSuchBetter]

First of all, much respect for going to the trouble of level matching properly, etc. I gather that this needs to be done with the headphones connected, but assuming you did that, I personally have no further notes on method.

Based on the graph posted earlier I guess it's possible you're hearing a bit of distortion, especially if you're listening loud. In that case, you might be "liking flaws".

When it comes to (a little bit of) distortion this is actually super common. People DO generally enjoy a bit of harmonic distortion - I can tell you it's actually pretty rare not to add any harmonic distortion during the production of a record if you're starting with super clean sounds... I mean, look at the entire world of guitar tones and you'll see what I mean. So when a piece of gear (like a tube amp, or maybe this amp) adds a little more... sometimes it sounds good.

So if you were hearing a little extra THD and you liked it... that's not a surprise, nor is there anything wrong with that per se, it just goes against the philosophy of high fidelity a bit, but if you like the sound, hey, it's your setup.

Thanks! I try to do things properly. I simply can’t lie to myself and need to know exactly what something is and why!

You know what? I did not do this with headphones connected. I took a 1/4 TRS and went from each amp while using the other end to test the signal. How does one do it with the headphones in?

Interesting points on the distortion! I could see that being a factor for my liking. Maybe that’s also what cuts certain instruments through better and helps me hear better for mixing. I know some of it can be a placebo but it really did help me dialing in certain aspects such as compression - it sounds like it translated on my monitors but I’ll have to listen again on fresh ears. For all I know I’ll hear it today and the whole mix will be clipping haha.

 

[MoreExpensiveSuchBetter]

@MoreExpensiveSuchBetter, thanks for stepping up and improving your method!

Do we have any objective data on the SPL Phonitor 2? I suspect performance will be similar to the version tested at ASR, and that it does not like the low impedance headphones.

Thank you! You guys have been incredibly helpful. I hope my thread will also help others who need something to reference in the future with your guys’ responses.

I don’t believe we have 3rd party measurements but the spec sheet looks very similar to the X that Amir measured. So not exactly great on paper! I keep leaning towards the distortion being what I like and somehow helps me hear things better. That being said kemmler3D mentioned I should be measuring WITH headphones so maybe I am approaching it wrong. Curious to hear back how one goes about that method.

Thanks again.

 

[kemmler3D]

Thanks! I try to do things properly. I simply can’t lie to myself and need to know exactly what something is and why!

You're in the right place, bud!

You know what? I did not do this with headphones connected. I took a 1/4 TRS and went from each amp while using the other end to test the signal. How does one do it with the headphones in?

This, I am not sure. But previously in the thread there were comments that it needs to be done with a load connected. I suppose the output voltage varies with impedance... the idea is to level-match the output so if the output varies with impedance then this makes sense. How to do this physically, dunno, never done it.

Interesting points on the distortion! I could see that being a factor for my liking. Maybe that’s also what cuts certain instruments through better and helps me hear better for mixing. I know some of it can be a placebo but it really did help me dialing in certain aspects such as compression - it sounds like it translated on my monitors but I’ll have to listen again on fresh ears.

I'm sure you know that mixing on headphones is considered suboptimal, so we'll just skip past that, but I would say you should definitely not mix with a known high-distortion monitoring device. If you need more distortion for something to cut through the mix, add it in the mix. Otherwise your mixes are going to come out a bit lifeless, no?

THD from amps is dynamic and often euphonic - like any of the good "tube enhancer" type plugins. I think this is why people like them, but it's also exactly why you shouldn't use one for mixing. It's no different than adding a tube enhancer plugin on your master channel and then turning it off when you export!

For all I know I’ll hear it today and the whole mix will be clipping haha.

Always interested in hearing how it goes!

 

[MRC01]

Good discussion and you are on the right track.

When performing a DBT, it can be helpful to ignore preference. The goal is to hear differences, not preferences. Is X A, or is it B? Not which do you prefer. You may have a preference but that is irrelevant to the test. You don't even have to characterize the difference, though you can if it helps. But the most subtle differences resist characterization. For example subtle differences in level don't sound like level differences, but sound "leaner" or "richer".