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SMSL H300 headamp - no reviews?

Music1969

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Their published measurements look great:
  • 47k ohm input impedance - nice
  • 0 ohm (near) output impedance - nice
  • Huge output gain - nice

Nobody talking about it?
 
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Well I got another in tonight, second H300 and put it on a DO300 DAC. It's sound amazing connecting the DAC with USB optical cable to a powered USB hub. I've got an A70Pro and also an SMSL SP400/M400 to compare it to and it competes with everything. The functional issue is having to put it on a vented monitor riser as the bottom gets so hot it'll singe your fingers. I wouldn't leave this on top of a DAC or leave it on at night. When they say less than 50w they mean it. I'm going to pull out the watt meter and see how much it's drawing at idle and when in use.
The last week I've been using a Topping A30Pro daily, and prefer the sound from this quite a bit. The A30Pro gets warm, but not as hot as the bottom of this. I'll get the laser thermometer and wattmeter and post a real review just from a functional point of view. The volume wheel is small but precise. At least I have a pair of Hifiman HE6se so I can give it a real workout later.

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I am waiting for mine, but yeah no review yet I hope I didn't make a mistake, but smsl is a well-known brand with many amps on the marked I hope (and bet) that it will measure well, (otherwise I wasted my money)...
if you find any reviews let me know..

But yeah that tiny volume knob is a bit sad..
 
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Seems excellent just like the other 72574613 headphone amps released this year alone. So not very exciting for me at least.
 
Internally, it looks great even if way overengineered. Externally, that small volume knob is a problem when it is the only method of volume adjustment. The range of gain control is excellent, though.
 
Specs are insane, but those dip switches aren't really meant to be used other than in a set-it-and-forget-it way, I guess. Should've gone with even more retro ones like the ones on spl Phonitor devices.
 
Agreed on the smallness of the knob. Hopefully if this is reviewed by @amirm , he can comment on his experience with the volume knob
 
Just give them 2 weeks and they will probably release another amp. It's kinda time for a D400 DAC anyway so they better release a H400 amp :))
 
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Their marketing says volume knob has a special design

They know the issues of small vol pots - SMSL have been around a while.

Still - Amir's measurement will either confirm or debunk their claim
 
Seems great for the price and I noticed a jab at Topping with the mention of voltage protection lol

What seems really good is the price around 300usd.
Hehe. Maybe not so much a jab as it is a declaration of stating that they have their s*** together. It might not be right, but some people lump all these Chinese audio manufacturers together with regard to quality expectations.
 
Maybe the puny volume wheel and retro look. It seems like a direct competitor to the A30Pro as far as performance goes. I use SMSL amps and DACs for a daily driver, just that orange power button would need a silver sharpie :)
If it runs cooler than the A30pro and has the same power on all connectors I'll grab one when they go on sale or hit the secondary market. The 50mv test for noise floor is the big one for me since getting into IEMs.

At least this Chi-Fi piece HAS a volume wheel lol, unlike say the Topping D70. Boy some of these things are focused too much on significant digits being zeros and not on ergonomics...
 
Hehe. Maybe not so much a jab as it is a declaration of stating that they have their s*** together. It might not be right, but some people lump all these Chinese audio manufacturers together with regard to quality expectations.
Well... didn't SMSL and Topping release a unit with almost exactly the same internals ? I don't know the models but some guy showed almost identical menus between 2 products. Maybe it was just they used the same chip tho, so same features.

I always get the impression these are just made in some big factory in Shenzen and "branding" is an afterthought, but that could be wrong.
 
Seems great for the price and I noticed a jab at Topping with the mention of voltage protection lol

What seems really good is the price around 300usd.

I agree. Cheap is good. especially nowadays lol. It also means you can jump in and compare these to expensive units easily.

The power output on this amp seems really scary tho. 5 Watts at 32 ohms ? holy moly. I feel like that's the design max on some headphones.

Especially with that little volume pot. I'd be worried about overdriving my headphones by accident a huge amount.
 
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At least this Chi-Fi piece HAS a volume wheel lol, unlike say the Topping D70. Boy some of these things are focused too much on significant digits being zeros and not on ergonomics...
Hi @milkplatoonblueberry and Welcome Aboard!
I know you don't mean this in a derogatory manner but let's avoid the term Chi-fi as it can have negative connotations for such companies. Thank you for your cooperation and understanding. ;)
 
Why of course ! Forgive my absolute boorishness !

I really want to give this amp a try out and see what's it's like.

I'm mostly interested in seeing if cheaper products with a focus on high-spec written measurements, and with very high power output stack up sound wise and in use to more expensive japanese gear. I shall report back.
 
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I am waiting for mine, but yeah no review yet I hope I didn't make a mistake, but smsl is a well-known brand with many amps on the marked I hope (and bet) that it will measure well, (otherwise I wasted my money)...
if you find any reviews let me know..

But yeah that tiny volume knob is a bit sad..
I know this is an older post but I am looking at buying the S.M.S.L H300 and was wondering what you thought of it. Thanks.
 
I know this is an older post but I am looking at buying the S.M.S.L H300 and was wondering what you thought of it. Thanks.
I have it for some time, is nice, clean.. a lottt of power, probably more than needed...
The only thing I can think of is that it gets a little hot especially if your room temperature is more than 20 degrees
 
I just got an H300 and a chance to compare it to one of the A30Pro's I've been using the last few weeks. The sound reminded me right away of the Sabaj A20H which is 1/3rd the price, has digital volume control for perfect channel matching, and doesn't run as warm. The design is sturdy and vented on the side, it's warm but no more so than the A30Pro. I've had a Gustard X26 Pro which runs hot, these aren't even close to that.
The H300 sounds fine, if you have an A30Pro I wouldn't suggest switching though. The volume wheel on this was scratchy/grindy after 3 oclock and felt like it got stuck towards the end. Will be sending this model back, but at least I could do a comparison to the A30Pro while having them both. The switches are fine except the gain switch. I learned right away to turn the volume wheel down before snicking the gain switch, because it's ridiculously easy to overshoot into high gain when aiming for medium. I was able to measure channel balance and it never deviated more than .2db and most times it was .1db or even. I use a 3.5mm male to male cable into the line in on the sound card, and on digital amplifiers both channels are a perfect match through the range, so I think it's fairly accurate. Every model is different, but it's within factory spec.

It's a simple design, transparent like most amplifiers out there today, and I'm sure if it gets measured it'll do well. This doesn't have venting on top, so if you have a cat, at least you'll never have to wonder where they're sleeping ever again. The volume wheel is small but not as annoying as I thought it would be (despite this one is defective like several of the Schiit Magni's I've had over the years with the scratchy/grinding problem).

PXL_20240322_165604664.jpg


If you get one, I'd order some thick round rubber feet on Aliexpress or Amazon to give it some airflow underneath. These are the ones I use. Just little speaker feet, but small enough to fit under an amplifier too. They come with 3M sticky pads to attach them.

PXL_20240322_213519135.jpg

Comparison:
Sabaj A20h has digital volume, 1/3 the price, almost exact same sound, less power (but still enough for the He6se with a 5 volt DAC). They're becoming hard to find, and the connectors on the back are annoying, also the XLR on the back are upside down, so you need a 3ft cable to twist enough usually.
The A30Pro is pretty evenly matched for power, better controls, and much better volume wheel. The vents are a dust magnet for pets. Also it has the same power on all headphone jacks, the H300 has different gains on SE and balanced. In low gain it's amazing with sensitive IEMs (95 on the 50mv test, completely silent noise floor).
The H300 gain switch is a recipe for disaster if you have easily blow-uppable headphones like the DT900/700 Pro X and use the switch often. Both the A30Pro and this will raise a 10x12 room temperature by 1 degree F if you leave them on all the time. Both surface temperatures measure with a laser thermometer too close to call on the hotspots.

Personally, I would save money and get the Sabaj A20H since they sound identical and perfect channel matching. The A30Pro is a sure thing as long as you don't have dust issues.
The best headphone amplifier stacks I've heard are my current SMSL SP400/M400 and also the Topping A70Pro/D70Pro Octo I just put together this month. I'd either scale back to the A20H or save up for the SP400 or A70Pro and sit either on the SMSL DL200 which is my permanent DAC, since it's big enough to sit almost any amplifier on. The H300 is a good amplifier in a crowded field, there's just no standout feature that makes it a must buy. It looks really nice on the SMSL DL200, but at this price so does a used Topping A90. Even the Topping L70 would be a great choice at the right price in comparison.

For myself, I've got a Topping A70Pro coming next week for $362 during the Aliexpress sale running through March 27th. It's going to be my permanent amplifier at that price with the DL200 under it.
In case you miss it or need to save up, the next ones are:
June 12th Summer Sale
Brand Shopping Week (August 18-21)
Then Singles day November 11
Black Friday Nov 20th

Those are the really big discount sales each year, the others are pretty minor for discounts compared to those.

The H300 is a nice amplifier, but you won't hear anything you likely haven't heard before. The headroom is great if you actually need it, but the thermals might be an issue for some unless you love all day warm coffee without having to go heat it up... I also have the Topping A50 III / D50 III stacking coming next week, will write up impressions when I get them to compare value for money and if the built in parametric EQ the DAC has works well.
 
Their marketing says volume knob has a special design

They know the issues of small vol pots - SMSL have been around a while.

Still - Amir's measurement will either confirm or debunk their claim
This is what im looking forward to. What is a "greatly reduced channel imbalance" as opposed to perfect.
 
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