[mrarroyo]

 
I first heard of this amp from an Aussie Head Fi member who praised its performance when he uses it to drive his AKG K1000. I am always on the lookout for good sounding and low price audio gear and since I am also familiar with the HLLY brand I contacted David Gao to see if he could send me a sample unit.
 
I received the TAMP-20 on Wednesday, September 8 of 2010 and the unit has about 110 hours of burn in. The impressions bellow are initial ones to be annotated with additional listening time and additional burn-in. As you will read I am very favorably impressed, not perfect by any means but darn enjoyable and one heck of a value!
 
Just to get it out of the way, the following are some improvements that I would like to see:
 

• The LED light is way to bright, should be toned down.
• The PSU plug to the back of the amp is finicky and if it is not fully inserted the unit will not turn on.
• The feet are made of a very hard plastic which causes the unit to slide easily. I would suggest a softer rubber material to allow both vibration damping and better grip.
• The speaker outs (4) are three way and work fine. However although pictures of the back are posted a note should be added to emphasize that cables with small ends should be used.

 
Now for some impressions! I have used the amp in three configurations, the first driving headphones using an AKG K1000 pigtail (speakers to 4-Pin Plug). Since I was interested in pursuing possibilities I took a  DIY made 4-Pin Plug to Senn HD580/600/650 cable and very carefully listened to a Senn HD580. I was quite surprised by the sound since IMO the HD580 sounded quite good, heck even better than driven by some amps that retail for far more than the TAMP-20 going price of $118 including S&H ( http://cgi.ebay.com/HLLY-TAMP-20-Class-T-AMP-AMPLIFIER-Tripath-TA2020-chip-/150405564193?pt=LH_DefaultDomain_0&hash=item2304dec721 ).
 
Next I tried the AKG K1000 and I have to concur with the Australian Head Fi member, the combo has a lot of synergy. Specifically the bass is both tight and controlled, surprising because my K1000 is a mid production unit instead of a bass heavy low serial number unit. I have listened to the K1000 mostly on units costing 15X to 30X and to hear a low price amp drive the K1000 as effectively is inspiring. I say this because like wine most vintners can make an excellent $200 Cabernet, but it takes a talented one to do the same under $25.
 
One other low price amp I have used to drive the K1000 is a vintage Marantz 2238B which can be picked up off eBay for under $100. This is somewhat misleading because these units sold for about $600 new in 1977, quite a lot of money 33 years ago. The Marantz tend to be on the warm side and when driving the K1000 the entire presentation is a bit mellower. Luckily I have both examples to draw on.
 
I then set a third rig, this time an Stax SRD7/Pro energizer modded by Birgir (spritzer) with his pro-board driving an Stax Lambda Pro. Here I am  not as convinced as with the K1000 or the Sennheiser. Perhaps it is due to not enough burn-in since I tried it when the TAMP-20 had about 60 hours of burn-in. However I will try again when the unit has about 200 hours of total burn-in, this however will have to wait since I will be sending the unit over to skylab and immtbiker to test and it may be another 3-4 weeks before I can do so.
 
BTW, I am using the HLLY SMK-III as a DAC from an iMac using apple lossless files and an inexpensive USB cable. The IC is an inexpensive RCA to RCA from Blue Jean Cable. The concept was to set up an entry level (cost wise) rig capable of decoding the files and able to drive dynamic headphones as well as electrostatic ones via an energizer box. Overall I believe HLLY has a hit with both units (you can read more on the SMK-III on a separate thread in the source forum) and both units can be purchase new for under $450.
 
I look forward to reading both of skylab and immtbiker impressions. Hope they get a kick  out of listening to this two wonderful sounding units that are so affordable. I will add additional thoughts over the next couple of days before shipping the units out and final thoughts in about a month following their return.
 
I would like to thank David for making the units available. Below are some pictures for  your enjoyment. Much more to come ...
 

 

 

[mrarroyo]

Reserved for future comments.

 

[brendon]

Very nice review !

 
What are the sort of precautions are to be taken if we are driving headphones directly from speaker terminals ?
 
Did you use some sort of impedance adapter for the HD580 ?

 

[mrarroyo]

Hi Brendon, I used my "calibrated fingers" to very gradually increase the volume. 

 Honestly I first tried it with the K1000 which many drive with speaker amps to get a "feel" for how the volume pot "behaves" then I used the HD580.

 

[brendon]

Ah I see.

 
So just for my information, what position was the volume pot for the K1000 and for the HD580 ?
 
This could make for a cheap amp to try the HD650s with.

 

[Bojamijams]

I'm a little confused. This doesn't seem like a headphone amp. Why no 1/4" jack at all? How is one supposed to drive headphones without some kind of a strange adapter?

 

[Blackmore]

Nice to see another good budget T based amp, reminds me my first TrendsAudio TA 10.1, which to me still a very good choice for K1000, especialy with audiomagus mods http://www.audio-magus.com/product_p/ta10vm.htm , however they dont offer such anymore.
 
Would be interesting to read more about it, maybe also some impressions vs. RW.
 
THX

 

[mrarroyo]

Quote:

Ah I see.

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So just for my information, what position was the volume pot for the K1000 and for the HD580 ?
 
This could make for a cheap amp to try the HD650s with.

Good questions and very dependent on the output of the source (2 Vrms being "standard" versus "whatever") also on how "hot" is the recording. With the K1000 using the AKG pigtail the volume pot ranged from 9 o'clock to 11 o'clock. I should mention that as a norm I listen at very low levels, however during the testing phase I got a bit carried away and raised the volume higher than normal. The volume pot with the HD580 ranged from a bit past 8 o'clock to about a bit past 9 o'clock.

 
Quote:

I'm a little confused. This doesn't seem like a headphone amp. Why no 1/4" jack at all? How is one supposed to drive headphones without some kind of a strange adapter?

It is really a 20 wpc stereo amp for speakers. However the AKG K1000 can be driven by this type of amp as well as an Stax electrostatic via an energizer box like the SRD7/Pro I used. I have also read of some users using amps like this to drive some of the newer orthodynamic cans, but I have not had the pleasure of using this kind of amp in such a configuration.

 
Quote:

Nice to see another good budget T based amp, reminds me my first TrendsAudio TA 10.1, which to me still a very good choice for K1000, especialy with audiomagus mods http://www.audio-magus.com/product_p/ta10vm.htm , however they dont offer such anymore.
 
Would be interesting to read more about it, maybe also some impressions vs. RW.
 
THX

I do plan to do such a comparison when I get the TAMP-20 back from Skylab and immtbiker. The month that it will be out on loan will allow the RWA rig to burn in following the LFP-V upgrade to the  30.2 and for the new Isabella which replaced my Isabellina.

 

[satkinsn]

Very good read - thank you.
 
The most exciting thing in audio (to me) is the low end, and how good a sound you can get for little money.
 
If you have a chance, (I'm new at the headphone end of things) explain in more detail how you connect the phones (using an adapter?) to the hlly.
 
scott a.

 

[dlaloum]

For running "normal" headphones with a speaker amp, you should connect something like the ART Headtap - it is a resistor network and will protect your headphones.... as long as you don't try to pump more than 50W through it.... if you did you would fry your ears in the second before your Headphones and the Headtap melted down... - on 2nd thoughts problem solved, no hearing = no headphones or amps = much more money saved!

 

[mrarroyo]

Quote:

Very good read - thank you.
 
The most exciting thing in audio (to me) is the low end, and how good a sound you can get for little money.
 
If you have a chance, (I'm new at the headphone end of things) explain in more detail how you connect the phones (using an adapter?) to the hlly.
 
scott a.

 
Hi Scott, if you look at the 1st and 3rd picture you will see a mult-icolor cable. This is an AKG K1000 "pigtail" which is intended to be connected to the speaker out tabs or an stereo speaker amp (3rd picture). This muli-colored wire ends in a female 4-Pin plug and you then must have your headphones terminated to a male 4-Pin plug like the one depicted below for a Sennheiser HD580/600/650. Hope this helps.
 

 

 

[mrarroyo]

Ok, the TAMP-20 and the SMK-III have been shipped to Skylab who will then ship them to immtbiker. Look forward to reading their impressions in the next month or so. Cheers!

 

[Blackmore]

Hey Miguel, you shouldnt change your avatar, cos its pretty hard to concentrate on topic now

 

[rosgr63]

Miguel how does it compare to the 30.2 driving the K1000?
 
Blackmore you've got a good point!

 

[Skylab]

Miguel was nice enough to loan me the HLLY Tamp-20.  I used it with my Hifiman HE-5LE headphones, since I had the right cabling for that, and since these planars like juice.
 
The sound from the T-Amp 20 was plenty dynamic, and it had very powerful bass with the HE-5LE.  It was able to drive the HE-5LE with absolutely no problems at all (although this is something most of my better headphone amps can also do).  However, in absolute terms, I thought the overall sound was a little shrill, and the treble is a occasionally just a little grating and brittle, and it sometimes sounded kind of thin in the midrange.  The T-Amp 20 sounds a little too much like what people stereotype solid state as sounding like (which may or may not be a bad thing, depending on your proclivities).
 
But that is in comparison to the much more expensive Meier Concerto.  Admittedly, the T-Amp 20 is nicely built, and fairly inexpensive, and will muster enough juice to power an efficient pair of speakers pretty well (unfortunately, I don’t have anything that could be considered an efficient pair of speakers).  And taken in this context, the sound I got from it was really very good.  It was certainly good enough that I could easily tell the difference between the Nuforce uDac as a source versus the HLLY SMK-III DAC. 
 
Further, the HLLY T-Amp 20 sounded a little better than the Sonic Impact 15 WPC T-Amp II which I still have around.  The SI T-Amp II was $139 when available - $20 more than the nicer HLLY.  The SI I also thought was a little thin, gritty, and brittle, in absolute terms.  But for the money, both are quite good.  The HLLY is smaller and nicer looking.  It’s small enough I would for sure buy one just to have it around, if I didn’t already have the SI around.