[Pale Rider]

Thanks Ken; much appreciated. Happy New Year!

 

[millionmonkeys]

Hi

The Trends Audio guys are offering an upgrade tube called a Russian 6H23n. They want something like an additional $70 for this upgrade. Do you think it would be worth it?

Thanks.

 

[gnostic19]

Quote:

Originally Posted by millionmonkeys /img/forum/go_quote.gif Hi The Trends Audio guys are offering an upgrade tube called a Russian 6H23n. They want something like an additional $70 for this upgrade. Do you think it would be worth it? Thanks.

It's $40 at audio-magus. Still, i won't pay that much. I'll go to a tube retailer and get one for 10-20 bucks.

 

[millionmonkeys]

Sorry the price difference I mentioned is bigger against the special introductory offer and the diff is only $40 for RRP. Aparently there is a different outout capacitor used in the more expensive model as well.

 

[KB]

Ok folks I have a small shipment of these in stock now. Here are some photos. I only have had a few hours to mess around with it but I can say that I really like it. I have a feeling it in improve a lot once it gets burned in. Here are some things to keep in mind. Set the bias after a few hours, I would do this as you burn it in several times. Mine was off right off the bat. See instructions and photo below.

86 the stock tube! I swapped it our with a Bugle Boy and it made a pretty significant improvement.

I do not want to make any lengthy impression statements as it only has a few hours on it. I am certain that this will change once it gets some time on it, however so far the amp seems to really favor harder to drive higher impedance phones. My favorite headphone with this is the AKG 702, and 701s, in fact it drives the hell out of these phones. I also found that the best interconnect was the JenaLabs trio plus and fugue, by far as it tamed the tightness of the amp. I am hoping that it relaxes (I am sure it will) as it burns in. You do not want to use a silver IC with this amp, at least my new one does not.

To set the Bias;

Since each tube may derivate a bit in parameters, especially from different series, it
needs to re-tune the DC bias voltages to guarantee the machine is working in the best
point and performing the best sound quality.
There are two blue precise adjustable potentiometers (R3, R13) for tuning the DC bias
voltage of each channel. The DC bias has been tuned in factory. But after run-in for a
period or changed another tube, it would be deviated that the fine-tuning is needed.
Before you tune these, you need a screwdriver (take off the case), a small screwdriver
(turn the screw of the potentiometer) and a (digital) multi-meter to detect the DC bias
voltage.

1. Use screwdriver to take out the two upper level screws in the front panel &
another two screws in the back panel. Then, open the upper case.

2. Power ON the machine with no audio signal input.

3. Wait at least 5 minutes for the machine to run in.

4. Use the multi-meter to detect the DC voltage between the test point A(L) [red] in
the PCB & the GND [black] (e.g. the ring of the power switch or the outer ring of
those RCA sockets) of the LEFT channel.

5. Turn the screw on the top of the R3 potentiometer by a small screwdriver
clockwise or anticlockwise until the voltage as close as to +16.5V.

6. Then, repeat step 4 and 5 for the RIGHT channel by changing the test point to
A(R) [red] and turning the screw on the top of the R13 potentiometer.

7. Power OFF the amplifier.

8. Cover back the upper case and tighten the screws.

Tube Rolling;

This amp should be a lot of fun to tube roll with.

Trends PA-10 supports two major tube series: (1) 6DJ8, 6922, 6N11, 6H23n, ECC88,
E88CC, etc…, and (2) 12AU7, 5963, 5814, ECC82, etc… If you change the tube
within the same series, it needs to re-tune the DC bias voltages ONLY. If you change
the tube from another series, it needs both to re-tune the DC bias voltages and re-set
the jumpers.

David at Trends also told us;

DIYers can also try to upgrade the coupling caps of audio output (C3, C6 - block 10uF caps) and headphone output (C4, C7 - tank 1000uF caps). The power filtering caps C2, C5 can also be upgraded.

For the driving of low impedance base speaker, it should be the responsibility of the power amplifier. Trends PA-10 cannot help much on this. But, for driving the power amplifiers, PA-10 should perform good, even in low-bass. This can be experienced by working PA-10 with our TA-10 as power amplifier. The full range of sound is improve significantly including the low-bass. You can also try this with other power amplifiers. This is because PA-10 is class-A tube amplification and using MOSFET as the output buffer to guarantee the driving power and impedance compatible with the power amplifiers.

So that makes for a nice bonus.

Anyhow I am real happy to have this wonderful affordable versatile small tube headphone amp in the mix.

Please report back here with your impressions and tubes that you have tried.

Ken

 

[KB]

Reporting back after a few days of playing burn in and the amp has begun to really smooth out nicely. There was a slight edge and frowardness to it out of the box, now there is a more relaxed tone. I am pretty amazed at how detailed the little amp is. I was using different sources and found that with my D25 its a wonderful match.

Ken

 

[klaila]

I just bought a PA-10 as a pre-amp for my Trends TA-10 amplifier. Together they drive a pair of JBL L830 speakers and are connected to my computer CD player.
The sound is amazing.
Our main stereo system is a Rotel amplifier with a set of B&W speakers, and I think my basement setup sounds better!
I played "The Day the Earth Stood Still" soundtrack (for theremin aficionados) on both systems: the Trends / JBL system blew my socks off.

 

[alksv]

Can anyone enlighten me? Does this little thing support the 1/4 or the 1/8 phone plug? (it looks like a 1/4, but it's so small I can't tell for sure)

Damn, I have the Darkvoice amp on order, but this tiny amp is so tempting (size, tube rolling, it's a Trends, coupling with TA10)... How do you feel does it hold itself against the more popular tube amps (Woo, LD, DV etc)? I'm thinking of building a nice Trends stack to use with the PC and HD650s (they will eventually release the DAC I hope).

 

[tjhmuse]

Thanks for all the info, Ken. Much appreciated. I'll be looking forward to some more reviews, before I decided whether or not to pull the trigger on this amp.

 

[KB]

Quote:

Originally Posted by alksv /img/forum/go_quote.gif Can anyone enlighten me? Does this little thing support the 1/4 or the 1/8 phone plug? (it looks like a 1/4, but it's so small I can't tell for sure) Damn, I have the Darkvoice amp on order, but this tiny amp is so tempting (size, tube rolling, it's a Trends, coupling with TA10)... How do you feel does it hold itself against the more popular tube amps (Woo, LD, DV etc)? I'm thinking of building a nice Trends stack to use with the PC and HD650s (they will eventually release the DAC I hope).

Its a mini (3.5mm) plug. mine is flat out fantastic, for the $$ its tops. I love this thing.

VS the Woo Audio WA6 I have its not quite all that but then again my WA6 was $1200.

Ken

 

[alksv]

I decided to give it a shot. Playing with it for 2 days now, it is rarely turned off.

I sure can agree with Ken that this thing is a lot of fun for its money. Its no 8th wonder, but considering its size, sound quality and tube rolling possibilities - it sure is hard to beat the little beast.

The sound was edgy out of the box, but I can confirm Ken's observations that with burn-in time it's beginning to smooth out. The stock tube is junk of course, I tried some gold label ECC82 Teslas, the 6922 Tung-Sols and Electro-Harmonix, and my fav Saratov 6H23n-EBs with it, and it showed instantly. Actually, I loved Teslas most, the sound seemed more relaxed, with nice soundstage and separation, and of course rich bass. I listened to some of my favorite LPs (Jing Chi's live disc, Mahavishnu's Inner Flame and Wonder's Key Of Life), I usually rate hardware after them, and with this amp I was rocked. I bet it will just improve with time and I'm really looking forward to it as I'm already in love with the tiny bugger. It drives the HD650 effortlessly it seems. I might aswell make it my main amp to listen to as it makes me quite happy and that's enough for me to cure the upgraditis.

I'd say give it a shot if you have a chance. Its a lot of fun!
Now to mate it with the TA-10.1

 

[gregzx]

Quote:

Originally Posted by KB /img/forum/go_quote.gif Also providing a better power cable.Ken

Hi Ken! I am just curious - why would you provide a new power cable? What is wrong with the stock one?

 

[ttr]

Awesome photos, and what a interesting little pre/phono/head-amp! Any new information about the RIAA filter? (i.e. does the phono connection have it...)

 

[juno604]

Quote:

Originally Posted by ttr /img/forum/go_quote.gif Awesome photos, and what a interesting little pre/phono/head-amp! Any new information about the RIAA filter? (i.e. does the phono connection have it...)

The "phono" input is more a "low level output source" input in that sense it doesn't include RIAA and gain though clearly higher than the CD input, 6:1 approx. , is still a bit short for phono.
It can help with a low level output phono stage.

Cheers

j

 

[KB]

Quote:

Originally Posted by alksv /img/forum/go_quote.gif I decided to give it a shot. Playing with it for 2 days now, it is rarely turned off. I sure can agree with Ken that this thing is a lot of fun for its money. Its no 8th wonder, but considering its size, sound quality and tube rolling possibilities - it sure is hard to beat the little beast. The sound was edgy out of the box, but I can confirm Ken's observations that with burn-in time it's beginning to smooth out. The stock tube is junk of course, I tried some gold label ECC82 Teslas, the 6922 Tung-Sols and Electro-Harmonix, and my fav Saratov 6H23n-EBs with it, and it showed instantly. Actually, I loved Teslas most, the sound seemed more relaxed, with nice soundstage and separation, and of course rich bass. I listened to some of my favorite LPs (Jing Chi's live disc, Mahavishnu's Inner Flame and Wonder's Key Of Life), I usually rate hardware after them, and with this amp I was rocked. I bet it will just improve with time and I'm really looking forward to it as I'm already in love with the tiny bugger. It drives the HD650 effortlessly it seems. I might aswell make it my main amp to listen to as it makes me quite happy and that's enough for me to cure the upgraditis. I'd say give it a shot if you have a chance. Its a lot of fun! Now to mate it with the TA-10.1

Vinnie is reccomending JJ tubes, has anyone tried these?

On the Power supply, no I have not have a chance to check into any mods yet. But it would be killer to run this off a SLA battery (24V)

Ken