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NAD: Marshall DSL20HR Head

Posted: Tue Apr 03, 2018 11:16 am
by culturejam
Overall, I really like it. I'll break down what I see as the pros and cons:

PRO:
• Tons of gain on tap on the red channel, but it never gets fizzy.
• Low-end is massive t but can be mostly dialed out if desired (Bass control + Resonance control)
• The tone stack is very responsive and works in a logical way
• Sounds *phenomenal* when cranked and *really really good* at lower volumes...this is all on the 20W mode
• It's 20W but still has EL34s, but it's cathode biased instead of fixed. So it's still got a "big bottle" sound about it without being a total beast watts-wise.
• Digital reverb is pretty decent. Better than a Belton brick, but not as good as a dedicated DSP pedal or rack unit. A lot of people probably won't like it, but I think it's fine for general use.

CON:
• The green (clean) channel can't ever get totally squeaky clean (with humbuckers anyway), but it also doesn't ever top out with a nice crunch. It goes from sorta-clean to not-quite-driven.
• In the 10W mode on the red channel, the same tone is mostly still there as 20W, but there is a fair loss of high end which requires an EQ adjustment to get it close to the 20W mode. Still, it's impressive and a noticeable volume reduction. I marked this a con because I had read many comments saying "it sounds exactly the same at 10W as 20W", but I'm just not hearing that.

Not tested yet: effects loop, emulated output jack.

Other notes:
• The EL34s are JJ brand and matched (see photos below). The silkscreen says Marshall, but the shape is a dead giveaway...as is the JJ logo sticker on the base. :)
• The phase inverter appears to be Chinese, but V1 and V2 appear to be JJ as well. Silkscreen markings are identical to the EL34s, and I compared the internals to some JJ 12ax7s I have, and they look nearly identical (same getter, same plate size and configuration, etc).

Enough yapping. Here's some photos.

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Re: NAD: Marshall DSL20HR Head

Posted: Tue Apr 03, 2018 11:43 am
by BetterOffShred
Beauty!! I find cathode bias compresses more than appropriately set fixed bias, which can be a good thing.

20 watts with 2 EL34's is interesting. Wonder why they didn't use 6V6's.. 2 EL34's should be good to 45 or 50 watts, iron permitting. I would love to see tube voltages from this amp in both modes..

I've always liked the Marshall DSL tone, and it's cool they have offered it in a smaller package.

Thanks for the review. :)

Re: NAD: Marshall DSL20HR Head

Posted: Tue Apr 03, 2018 1:07 pm
by Pete
This might be kind of a hard question to answer, but how would you describe a DSL tone compared to a JCM tone?

Re: NAD: Marshall DSL20HR Head

Posted: Tue Apr 03, 2018 2:06 pm
by BetterOffShred
Pete wrote:This might be kind of a hard question to answer, but how would you describe a DSL tone compared to a JCM tone?
IMO the DSL tone is tighter and higher gain, but still retains some of that huge mid roar that is instantly recognizable from the JCM stuff. The 2204 and 2203 I consider to be some of the best rock amps ever devised, the DSL and TSL kind of take it a litter further. They are obviously meant to compete with the Rectifier series from Mesa, and they aim for the same thing tone-wise. Just my opinion. They sound good at lower gain too, but you're not going to get a Princeton or deluxe reverb out of them either.

Re: NAD: Marshall DSL20HR Head

Posted: Tue Apr 03, 2018 9:00 pm
by culturejam
BetterOffShred wrote:20 watts with 2 EL34's is interesting. Wonder why they didn't use 6V6's.. 2 EL34's should be good to 45 or 50 watts, iron permitting. I would love to see tube voltages from this amp in both modes..
Maybe it's actually not a class AB push-pull setup? Could be single-ended with the tubes in parallel. That should be about 20W. The manual nor web site indicate operation class or anything else.

EDIT:
But probably it's AB push-pull at lower voltage. The folks at Amp Garage have a thread on the similarly outfitted 2525H: http://ampgarage.com/forum/viewtopic.php?f=6&t=30885

Re: NAD: Marshall DSL20HR Head

Posted: Tue Apr 03, 2018 9:03 pm
by Chankgeez
Is that the purple Clusterfuzz? :love: :snax: :lol:

(Nice amp, btw. :thumb: )

Re: NAD: Marshall DSL20HR Head

Posted: Tue Apr 03, 2018 9:06 pm
by culturejam
Chankgeez wrote:Is that the purple Clusterfuzz? :love: :snax: :lol:
I *never* miss an opportunity for gratuitous product placement. :lol:

Re: NAD: Marshall DSL20HR Head

Posted: Tue Apr 03, 2018 9:10 pm
by Chankgeez
:thumb:

Re: NAD: Marshall DSL20HR Head

Posted: Wed Apr 04, 2018 12:15 am
by BetterOffShred
culturejam wrote:
BetterOffShred wrote:20 watts with 2 EL34's is interesting. Wonder why they didn't use 6V6's.. 2 EL34's should be good to 45 or 50 watts, iron permitting. I would love to see tube voltages from this amp in both modes..
Maybe it's actually not a class AB push-pull setup? Could be single-ended with the tubes in parallel. That should be about 20W. The manual nor web site indicate operation class or anything else.

EDIT:
But probably it's AB push-pull at lower voltage. The folks at Amp Garage have a thread on the similarly outfitted 2525H: http://ampgarage.com/forum/viewtopic.php?f=6&t=30885
Yeah it's pretty common with these 10/20 and 7.5/15 etc switchable guys for there to just be another lower voltage tap on the power transformer that runs everything like 60 VDC or so lower. I had dreams of building a dark terror and was planning on using some bigass resistors to just drop B+ the old fashioned way :thumb:

Also you don't see many high gain single ended amps. I know Merlin has a schematic out there for one, but they never have the grunt of a push pull.

I'm jealous. I'd love the mini rectumfrier..

Re: NAD: Marshall DSL20HR Head

Posted: Wed Apr 04, 2018 1:29 pm
by frigid midget
Dat purple clusterfuzz though :drool:

Re: NAD: Marshall DSL20HR Head

Posted: Thu Apr 05, 2018 11:25 pm
by culturejam
Popped 'er open tonight. Looks very orderly inside.

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Re: NAD: Marshall DSL20HR Head

Posted: Thu Apr 05, 2018 11:41 pm
by BetterOffShred
:drool:

Re: NAD: Marshall DSL20HR Head

Posted: Fri Apr 13, 2018 12:14 am
by culturejam
I got some better cleans with a 12AT7 in V1, for the record.

I put the stock preamp tubes back in so I could test the stock JJ EL34 power tubes vs a set of JJ E34L tubes. As expected, it's not a night/day difference. But I could hear some differences.

The E34L tubes break up a little bit later than the stock tubes and the overall sustain on the dirty channel is slightly less. It's maybe a 10-15% difference, but it's enough to notice. I don't have golden ears, so if I notice it, it's probably really happening. :)

On the clean channel, there's not much difference other than the slightly less gain of the E34Ls, which to me is an improvement.

The other main thing I can hear is that the E34Ls have less hum/noise than the stock tubes. Again, not a "game changer" difference, but I noticed it.