Help me choose a JLH '69 amp

[Rallen]

I've decided to pull the trigger on a chinese JLH-based amp.
However - there's quite a few different versions, and I can't decide which one to pick. Any recommendations?

Upgraded version Hood 1969 ON 15024/15025 Gold seal power tube class A 18W + 18W hifi fever amplifier finished-in Amplifier from Consumer Electronics on AliExpress

- Is this 2x18W as apposed to the others 2x10W? This seems to be built with new parts where the other use repurposed parts. Is this a pro or a con?
This one weighs around 4,7 KG




Buy Products Online from China Wholesalers at Aliexpress.com

Buy Products Online from China Wholesalers at Aliexpress.com

- These 2 looks pretty similar. I guess both use repurposed parts? Seems to weigh 5-6 kgs




Online Shop LP Spirit T-01 Pure Class A HiFi 2.0 Classic 1969 Wiring Construction Power Audio Amplifier 10W+10W Linear Power Supply DC24V/5A | AliExpress Mobile

- This seems to have a separate power supply.



My long term goal is to pick up a real power amp, so the next thing I'm probably going to buy is a line stage that I can re-use when getting the "final" power amp.

I'll probably go for something like this:

Buy Products Online from China Wholesalers at Aliexpress.com

Will the volume control on this line-amp allow the JLH to play louder?
And will the 2 volume controls conflict in some way?

 

[Rallen]

Other suggestions would be greatly appreciated as well

 

[N101N]

I can provide my unbuilt design if you are truly interested. It uses JFET input amplifiers, appropriate voltage amplifiers and preferably lateral MOSFETs or generic MOSFETs.

 

[Ian Finch]

The first 2 JLH'69 amplifier products are similar to other completed amplifiers that have been discussed and compared in a few threads here. Since 2N3055 power transistors are now obsolete, kit assemblers have just changed to other types of TO3 style power transistors to suit the PCBs whilst still looking like the original parts. I have one of the gold colour versions branded "Krell" from a few years ago but it works just fine as it comes. In this climate and summer season where I live, I can feel the radiant heat from a metre away. However, you may quite enjoy that little extra warmth right now.

I doubt the power increase to 18W is real because the power transformer hasn't changed but 18W v 15W isn't going to be significant anyway. I haven't seen or read much that is informative about the T-01 product but it's obviously just the power amplifier boards in a small box, probably fan cooled and powered by a conventional transformer/rectifier in the second box.

Unfortunately, fans are also noisy and need care with the running speed, size and blade type to make it effectively silent. Bear in mind that the smaller the box and airflow volume, the hotter it will run and even at only a 10W +10W output rating, all straightforward class A amplifiers need lots of airflow and plenty of efficient heatsinking for a trouble-free life.

I don't have any more the seller's info. on that preamp as I don't need or use one at present. However, the volume control in the finished amplifiers is passive. Its just an adjustable attenuator in series with the input signal and shunted to ground. https://www.electronics-tutorials.ws/attenuators/l-pad-attenuator.html It will limit any drive benefit of a preamp so it might be advisable to bypass the amplifier's volume control if you want to include a full-featured preamp in the audio chain.

Personally, I wouldn't use a preamp if all I really needed it for is a source switch and volume control. There are simpler and better solutions for that but you may have do a little DIY to get there

 

[Ian Finch]

On a closer look at T-01, it seems that the power amplifiers are lying flat on the heatsink and apparently without fan cooling or natural airflow. That's gotta get toasty!

 

[jtgofish]

I have first one listed on loan from a friend [the claimed 18 watt one].It sounded a bit flat at first but I played around with different cables and speakers and have it sounding very good now.Build quality looks pretty good to me.I find it musically communicative with very good timing.Much better than the First watt F5 in that regard.

 

[Rallen]

Thanks for your inputs. I ended up ordering this version through an agent in China (its a little cheaper for both the product and the shipping that way):
???Hood 1969????hifi????????????????-???

Pretty sure its the same one as the second in my original post (18W+18W)

If the 18W aren't real anyway, would it be wiser to get the 10W version instead? I can get that on taobao as well:
Hood 1969???????? ?6????? ????-???

Main thing puzzling me is the weight difference...

 

[jtgofish]

For what they cost I think you should buy them all and report back on which sounds best!
From what am hearing from the 18 watt Weiliang version its strength is that it has no obvious weak areas rather than it being especially good in any particular area.You just listen to it and think-yes that sounds very pleasant and there is nothing there to annoy you like loose bass,poor timing or coarse treble.I have owned a great many amps and that is a surprisingly rare character and a highly commendable one.