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Home Theater => Audio => Amplifier => Topic started by: karipas on Dec 02, 2018 at 11:38 AM

Title: Class A solid state amp who has one?
Post by: karipas on Dec 02, 2018 at 11:38 AM
Hi,

I am planning to purchase a First Watt F5 kit this coming January...after the Christmas shopping spree and cutting my credit card bills. Anyone have experience on this amp, or would you recommend other kits?
Originally wanted to build a VTA ST-120, but I figure the F5 is cheaper to keep me busy and will comeback to the ST 120 later once I gain more confidence in building a bigger project.


Thanks.

Jojo
Title: Re: Class A solid state amp who has one?
Post by: accastil on Dec 03, 2018 at 02:49 PM
pre, kamusta na? still overseas?

sayang...im currently letting go of my B&K EX4420M monoblocks.
these are classA 225W monos with 2 working terminals for each piece.

these types sound very very quiet and refined. only drawback is power consumption.



Title: Re: Class A solid state amp who has one?
Post by: karipas on Dec 07, 2018 at 02:16 PM
Hi Allan,

Ayus naman kami. Oo dito na kami for good, pero last April umiwi kami.
Ba sayang nga kung madali lang mag ship from sa atin papunta dito. Pag may nagbebenta ng mga B&K dito ikaw naalala ko nung nag listening session tayo sa house mo. Para palang welding machine yan sa consumption. LOL

Gusto ko lang naman may mapagkaabalahan ngayon winter mukhang madali lang yung kit ng Firstwatt F5 medyo may kamahalan lang yung chassis kasi galing pa Italy.
... sa spring bubuo ako ng VTA version ng Dynaco ST-120 close daw sila ng tunog ng MacIntosh 240 kaya try ko.

Kaw musta na? I hope all is well with you and family too.


pre, kamusta na? still overseas?

sayang...im currently letting go of my B&K EX4420M monoblocks.
these are classA 225W monos with 2 working terminals for each piece.

these types sound very very quiet and refined. only drawback is power consumption.




Title: Re: Class A solid state amp who has one?
Post by: dv187736 on Dec 07, 2018 at 04:28 PM
You may want to try the Hiraga 20W or 30W super class A, or the Ovation SX (new is KX) class A amp from hifisonix.com.

PCBs for both are available from Jim’s Audio in ebay.com. They also have the PSU PCB boards for these.

You have to source locally the power transformer and the chassis/heatsinks or buy from aliexpress.
Title: Re: Class A solid state amp who has one?
Post by: karipas on Dec 08, 2018 at 02:48 PM
Thanks for this, please let me know why you are recommending this particular design? How does it sound with the others? My interest is peeked, estimated price comparison is that the Hiraga is significantly cheaper . I have a beginner skills, so a consideration of simple build is important.

You may want to try the Hiraga 20W or 30W super class A, or the Ovation SX (new is KX) class A amp from hifisonix.com.

PCBs for both are available from Jim’s Audio in ebay.com. They also have the PSU PCB boards for these.

You have to source locally the power transformer and the chassis/heatsinks or buy from aliexpress.
Title: Re: Class A solid state amp who has one?
Post by: darkangel69 on Jan 03, 2019 at 03:23 PM
Thanks for this, please let me know why you are recommending this particular design? How does it sound with the others? My interest is peeked, estimated price comparison is that the Hiraga is significantly cheaper . I have a beginner skills, so a consideration of simple build is important.

You may want to try the Hiraga 20W or 30W super class A, or the Ovation SX (new is KX) class A amp from hifisonix.com.

PCBs for both are available from Jim’s Audio in ebay.com. They also have the PSU PCB boards for these.

You have to source locally the power transformer and the chassis/heatsinks or buy from aliexpress.

Hi, you might want to consider a commercially made Class A amp based on Hiraga. I'm not using it anymore cause I already sold my fullrange MarkAudio Alpair 10p fullrange speakers. If in any case you can pm me for more details.
Title: Re: Class A solid state amp who has one?
Post by: t-bone on Jan 03, 2019 at 03:41 PM
I had a hot running Krell amplifier before.

Sounded great with ample power, deadly on the electricity bill.
Title: Re: Class A solid state amp who has one?
Post by: tony on Jan 03, 2019 at 04:19 PM
this is a Kampana amp built last Oct 27....
based on the Nelson Pass Amp Camp, 5 watts class A single ended mosfet amp...
total power consumption is around 48 watts, so at 10 watts output efficiency is around 21%
a tube single ended with about the same output is 98 watts power draw...

(https://scontent.fcrk1-1.fna.fbcdn.net/v/t1.0-9/44308406_2089049761116647_5153417025225228288_n.jpg?_nc_cat=110&_nc_ht=scontent.fcrk1-1.fna&oh=480d9522298ceafdf08842b8f7ecca62&oe=5CC54C8D)
Title: Re: Class A solid state amp who has one?
Post by: karipas on Jan 26, 2019 at 11:40 PM
Thank you all for the responses, I appreciate it very much! Sorry for the late reply, I guess I was late at the party.

So this is what happened, since I missed your responses and when I get my funds I am always eager to spend it right away, therefore I ended up getting a me Pioneer Spec 4 this time, I will be picking it up tomorrow and what it means is I have to move the project a bit farther off schedule, I but I am still determined to build either of the two.

@ Sir Tony di kaya ako kapusin sa 10watts? I thinking of 20 to 30 watter sana, but for starters maybe I may consider, how does it sound and estimated kit cost?
Thanks in advance.
Title: Re: Class A solid state amp who has one?
Post by: karipas on Jan 27, 2019 at 12:13 AM
I had a hot running Krell amplifier before.

Sounded great with ample power, deadly on the electricity bill.
Nice, Krells are a beauty! I once invited to DIY meet to pick up my SX1250 that was serviced by my tech, being showcased was a Pass amp on a humongous Krell housing driving huge JBL speakers in a 9' tall cabinets with authority in a warehouse.
The SX1250 is a wonderful receiver but was outclassed on that setting.
Title: Re: Class A solid state amp who has one?
Post by: dv187736 on Jan 27, 2019 at 04:45 PM
@Karipas

Sorry for this delayed reply. I just saw you comment of Dec 19 2018.

I had a friend build both my Hiraga and Ovation SX amps. Hiraga was chosen based on the simplicity of the circuit topology, fewer parts, and the many positive reviews/comments I’ve read. I needed to hear it for myself. True enough, it is a classic amp design. It’s able to drive my Wilson watt/puppy easily, unlike other higher powered amps i’ve tested before and after. The sound suits my preference. Best to read the comments (diyaudio.com) to get a better sense of what it sounds like but you have to hear one to decide, or take the risk as I did myself...and am happy I did.

The Ovation SX is also Class A, a recent design, and takes after Hiraga too but with Current Feedback (CF) topology. You can check out Hifisonix site. It has a very thorough documentation, including the build out instructions which you can download. I had this amp built because, well, it’s class A and at the time very impressed with the low-watt Hiraga. While the Hiraga sounds tube-like, the SX is more incisive(?) in its presentation but not fatiguing even on prolonged listening. Both amps excel in imaging and soundstage.

Between the two, I prefer the Hiraga. But that’s me.

I am recommending the two not just because of how good these amps sound but I think it easier to build with low parts count.

But if you really want one that is much easier to build than the Hiraga and Ovation, sounding good to boot, and 5-watts is good enough for you then the Nelson Pass AmpCamp (a.k.a. Kampana) per Tony is best. I built the original AmpCamp myself and in the process of completing my Kampana. 

Title: Re: Class A solid state amp who has one?
Post by: dv187736 on Jan 27, 2019 at 05:21 PM
@Karipas
I'm not sure if the photos will appear below. If not, you can just copy&paste to your browser if you want to see the amps.

(https://mensky.smugmug.com/Other/Miscellaneous/i-Qv4SgfN/A
https://mensky.smugmug.com/Other/Miscellaneous/i-Bq6vNBx/A
https://mensky.smugmug.com/Other/Miscellaneous/i-HHG2R84/A
https://mensky.smugmug.com/Other/Miscellaneous/i-VqNS7Hh/A
https://mensky.smugmug.com/Other/Miscellaneous/i-dQ6ZtJ4/A
https://mensky.smugmug.com/Other/Miscellaneous/i-rJTCb2b/A)
Title: Re: Class A solid state amp who has one?
Post by: dv187736 on Jan 27, 2019 at 05:24 PM
@Karipas
It did not work, just copy&paste to browser.

https://mensky.smugmug.com/Other/Miscellaneous/i-Qv4SgfN/A
https://mensky.smugmug.com/Other/Miscellaneous/i-Bq6vNBx/A
https://mensky.smugmug.com/Other/Miscellaneous/i-HHG2R84/A
https://mensky.smugmug.com/Other/Miscellaneous/i-VqNS7Hh/A
https://mensky.smugmug.com/Other/Miscellaneous/i-dQ6ZtJ4/A
https://mensky.smugmug.com/Other/Miscellaneous/i-rJTCb2b/A
Title: Re: Class A solid state amp who has one?
Post by: tony on Jan 27, 2019 at 08:22 PM
Thank you all for the responses, I appreciate it very much! Sorry for the late reply, I guess I was late at the party.

So this is what happened, since I missed your responses and when I get my funds I am always eager to spend it right away, therefore I ended up getting a me Pioneer Spec 4 this time, I will be picking it up tomorrow and what it means is I have to move the project a bit farther off schedule, I but I am still determined to build either of the two.

@ Sir Tony di kaya ako kapusin sa 10watts? I thinking of 20 to 30 watter sana, but for starters maybe I may consider, how does it sound and estimated kit cost?
Thanks in advance.


spec 4 is a good amp, class AB, power is dependent on your speaker sensitivity and your listening preferences...
Title: Re: Class A solid state amp who has one?
Post by: qguy on Jan 27, 2019 at 10:18 PM
Karipas,

Have you compared the  SX-1250 to the Spec 4
Title: Re: Class A solid state amp who has one?
Post by: karipas on Jan 28, 2019 at 09:52 AM
@Karipas
I'm not sure if the photos will appear below. If not, you can just copy&paste to your browser if you want to see the amps.

(https://mensky.smugmug.com/Other/Miscellaneous/i-Qv4SgfN/A
https://mensky.smugmug.com/Other/Miscellaneous/i-Bq6vNBx/A
https://mensky.smugmug.com/Other/Miscellaneous/i-HHG2R84/A
https://mensky.smugmug.com/Other/Miscellaneous/i-VqNS7Hh/A
https://mensky.smugmug.com/Other/Miscellaneous/i-dQ6ZtJ4/A
https://mensky.smugmug.com/Other/Miscellaneous/i-rJTCb2b/A)

Hi @dv187736, I got it, I am in love with those big caps :)
Thanks!
Title: Re: Class A solid state amp who has one?
Post by: karipas on Jan 28, 2019 at 09:56 AM
spec 4 is a good amp, class AB, power is dependent on your speaker sensitivity and your listening preferences...

Hi @Sir Tony, My speakers are efficient enough, the Spec 4 is now connected to my HPM 100. However was referring to your Kampana amp since it's 5wpc di kaya ako kaupsin if ever I try to build this one?
Title: Re: Class A solid state amp who has one?
Post by: karipas on Jan 28, 2019 at 10:49 AM
Karipas,
Have you compared the  SX-1250 to the Spec 4
I Qguy, I just got the Spec 4 today, I crossed south of the border kanina to pick it up. Dim bulb test muna to make sure it is working.

My initial assesment: Different presentations but I liked both, it will be a preference which flavor you want for the day.
The Spec 4 has the typical Pioneer house sound, a bit forward, no holds bard at the mid and top end, nice bottom presentation.

The Spec 4 is more akin to but has a more refined sound than my SA-9800ii/SA9500 which I regrettably sold a few years ago but very close; the SA-9500 probably can be your Spec 2 or 4 on a budget. I preferred the presentation of the SA 8800ii hence I kept it through the years using it now as a pre-amp for the Spec 4 while I hunt for a Spec 1.

Note that I've refurbed SA 8800II, all other mentioned where not, the result might change in the next few months perhaps. I said this because the  SX1250 became a different animal when I had the leaking filter caps replaced (I used to adjust the turnover to my bass liking and loudness switch to on; but now I play it just flat and the SX1250 sings wonderfully). I will have the Spec 4 professionally restored in the coming weeks, and since I had the SX1250 filter caps replaced I will do the recapping myself.

Oh and to add, I think the Spec 4 has a much bigger sound stage, better separation/imaging than the SX 1250 BUT to my ears the SX 1250 sounds sweeter and warm to my ears, slightly (just slightly) laid back than the Spec 4. :)
I think the Spec 4 is picky on pre-amp. I did not liked the presentation of my tube Anthem Pre 1 + Spec 4.

I am not good in describing but I hope this helps.

CD Material, Mediteranian Sundance - Al DE Meola, Mc Laughlin, DE Lucia
Title: Re: Class A solid state amp who has one?
Post by: qguy on Jan 28, 2019 at 08:05 PM
Try the SX-1250 pre on your Spec 4,  I bet it would become sweet and warm  :)    I tried the SX-1250 pre on my Rotel power amp and it became sweet and warm :)

I also had the SA-9500, compared to my other amp, that one was a bit grainy. sold it, never regretted it.
Title: Re: Class A solid state amp who has one?
Post by: qguy on Jan 28, 2019 at 08:10 PM
You mentioned, " it will be a preference which flavor you want for the day"  I think this is a good compromise,  My SX-1250 is warm and sweet and my Rotel driven direct from the DAC  is detailed and bit forward.  So i choose the amp I use depending on the music I want to listen too....
Title: Re: Class A solid state amp who has one?
Post by: karipas on Jan 29, 2019 at 06:09 AM
You mentioned, " it will be a preference which flavor you want for the day"  I think this is a good compromise,  My SX-1250 is warm and sweet and my Rotel driven direct from the DAC  is detailed and bit forward.  So i choose the amp I use depending on the music I want to listen too....

I think we have the same preference in gears. You were on point on the SA9500 being grainy, I regret selling it because it's a power house and I liked its industrial design but not necessarily miss the sound.

I might add on the Spec 4, I guess the previous owner has not powered this thing for awhile.
After I left it running for 4 hours, came back and plugged my cd player direct just using the attenuators...and woot woot, awesome balanced music, not forward in your face sound anymore. So plugged it back in with the SA 8800II, but this time I dialed the attentuators to max, so the volume is only controlled by the pre-amp of the SA 8800II.

Now I take back what I said about the Spec 4 sound similar to an SA 9500; no the SPEC 4 is far from that, it plays smooth and engaging, perfect Pioneer sound, I does sound highend.... I will do some experiment again this weekend before my tech takes it to refurb, I will also use the SX1250 as preamp as you recommended and report back.

To summarize, is the Spec 4 and SX 1250 worth restoring and worth the ridiculous price I paid for it? I can answer it with a BIG YES! We are so lucky to have and experience these wonderful gears.
Title: Re: Class A solid state amp who has one?
Post by: tony on Jan 29, 2019 at 12:45 PM
awesome pioneers, i too love those amps....pioneer is very easy to to repair based on experience....when i was still in the repair business about 20 years ago, more sansuis came to the shop than pinoeers, and the pioneers that came was such a joy to repair....

i would say those sansuis that had lawanit bottoms and plastic side casings from the middle east are the ones that burned out easily, that is why we called them sansunog...

but don't get me wrong, sansuis like the G series and the 9090db's are among the best sounding amps and receivers that i heard....the top model sansuis can sound even better than most pioneers....

Title: Re: Class A solid state amp who has one?
Post by: tony on Jan 29, 2019 at 12:48 PM
Hi @Sir Tony, My speakers are efficient enough, the Spec 4 is now connected to my HPM 100. However was referring to your Kampana amp since it's 5wpc di kaya ako kaupsin if ever I try to build this one?

it was mistaken for a 300b amp over at Lin Gomez's shop....so nturaly you want high sensitivity speakers to use..
Title: Re: Class A solid state amp who has one?
Post by: dv187736 on Jan 29, 2019 at 08:45 PM
@Karipas

Here's one Pioneer model you might to check out - model M22. It's Class A. It's the amp that got me in to class A amps.
http://www.thevintageknob.org/pioneer-M-22.html
Title: Re: Class A solid state amp who has one?
Post by: karipas on Jan 29, 2019 at 10:56 PM
@Karipas
Here's one Pioneer model you might to check out - model M22. It's Class A. It's the amp that got me in to class A amps.
http://www.thevintageknob.org/pioneer-M-22.html

Oh thanks! I've been eyeing the M-22 last November in case my build slip through the cracks. If not for the Spec 4 then I will have the  M-22 singing in my system, it was advertised at our local audio site 2 days after I hit the BIN on the Spec 4. No remorse though, this is what makes our hobby fun and interesting, waiting in anticipation and looking forward to what might come along in between then our wait list grows longer and never ending.

Title: Re: Class A solid state amp who has one?
Post by: tony on Jan 30, 2019 at 12:49 PM
the spec4 has a higher damping factor than the spec2
the spec4 used current mirror loading in the input ltp,
the spec2 used cascode in the input ltp......
the spec4 has higher open loop gain so that more feedback can be used to hep damping factor..
the spec4 is a triple darlington, the spec2 a darlington...
these differences probably makes for the possible differences in sounds...
power of 150 watts compared to 250 watts is not even 3db, i will not call it substantial..

overall i choose the spec 4........but these pioneers are amps to die for...
the spec 4 used separate psu's for the left and right channels but common supplies for both channels' input/front end..
M22 is more like the spec2 albeit biased class A...
Title: Re: Class A solid state amp who has one?
Post by: karipas on Jan 31, 2019 at 12:40 AM
the spec4 has a higher damping factor than the spec2
the spec4 used current mirror loading in the input ltp,
the spec2 used cascode in the input ltp......
the spec4 has higher open loop gain so that more feedback can be used to hep damping factor..
the spec4 is a triple darlington, the spec2 a darlington...
these differences probably makes for the possible differences in sounds...
power of 150 watts compared to 250 watts is not even 3db, i will not call it substantial..

overall i choose the spec 4........but these pioneers are amps to die for...
the spec 4 used separate psu's for the left and right channels but common supplies for both channels' input/front end..
M22 is more like the spec2 albeit biased class A...

Exactly my same thoughts from what I gathered on reviews and suggestions before pulling the trigger, sonic qualities of the Spec 4 favors my speakers and small listening room and the Spec 2 is around 400 to 500 more coins than the Spec 4 in my side of the fence anyways.
My funny story how I got the spec 4, so I visited the auction site in a dead hour 2pm at work, and voila 1h30min before closing with 0 bids; I have the class A plan but I have to at least take action in a heartbeat I placed $1 and let someone outbid me in the last few minutes but nada, .... guess the Spec 4 was really meant for me.
Next again will be class A, unless another opportunity presents.
Title: Re: Class A solid state amp who has one?
Post by: tony on Jan 31, 2019 at 07:29 AM
i coveted the Spec2, but since i make my own amps, what the heck?, the Leach Super amps sounded very good....a truly hifi amp......

btw, user feedback is really  OF value, it gives deeper insights as to what  worked better for guys like me who is into circuit design....

the Spec2 will work great in a multi- amp system powering the lows..
and the Spec 4 powering the mids and highs...
using electronic cross overs, a system made out of this will indeed be hard to beat...

electric bills? do not worry for as powerful as these amps are, they will not consume more than a 100 watts total for the two amps...

the dynaco st 70 with its measely 35watts per channel of power consumed more than 110 watts at idle depending on how hot you bias the EL34 output tubes...
Title: Re: Class A solid state amp who has one?
Post by: tony on Jan 31, 2019 at 07:35 AM
Class A? there is the Mark Levison ML2 or the Krell Ksa100...

i have heard about a dozen of these ML2's in a multiamped system of the late Bert Baksal, they are hard to beat...
Title: Re: Class A solid state amp who has one?
Post by: karipas on Jan 31, 2019 at 12:56 PM
Class A? there is the Mark Levison ML2 or the Krell Ksa100...
i have heard about a dozen of these ML2's in a multiamped system of the late Bert Baksal, they are hard to beat...

Nice and purty amps I am sure it's a killer setup  :o :o :o and I need those to heat my room in winter time, btw this picture was taken yesterday morning before entering the office @-19Celcius (feels like -36C with windchill)

But that direction is a slippery slope, I have barely scratched the surface of the vintage audio world, going that route might take away the fun instantly. I have a few more hobbies with those amps in the equation means I need some  compromise.  ;D

(https://farm5.staticflickr.com/4879/33059155738_7a73a6c77e_c.jpg)



Here some stolen shots of the Spec 4, not yet cleaned:
(https://farm8.staticflickr.com/7893/31993523967_75f83bbc54_c.jpg)
(https://farm5.staticflickr.com/4915/31993523597_0e9e40cdf9_c.jpg)

Nude...dusty but unmolested:
I am quite happy with the purchase:
(https://farm8.staticflickr.com/7886/31993524367_b8ee4bc17f_c.jpg)[/url]
Title: Re: Class A solid state amp who has one?
Post by: karipas on Jan 31, 2019 at 01:25 PM
electric bills? do not worry for as powerful as these amps are, they will not consume more than a 100 watts total for the two amps...
the dynaco st 70 with its measely 35watts per channel of power consumed more than 110 watts at idle depending on how hot you bias the EL34 output tubes...

Not too concern about electric bills, I believe mas cheaper dito kaysa dyan sa atin  :-[ . On weekends the receiver and amps will be running for 12hrs while we go shopping, grocery and errands,  my central AC is the worst takes about 65 to 75% of the electric bill in summer.

i coveted the Spec2, but since i make my own amps, what the heck?, the Leach Super amps sounded very good....a truly hifi amp......
btw, user feedback is really  OF value, it gives deeper insights as to what  worked better for guys like me who is into circuit design....

That Leach amp looks very serious, I see 12 transistors :D
Noted Sir Tony, I will keep that in mind I will report interesting finds, acquisitions et al

Title: Re: Class A solid state amp who has one?
Post by: karipas on Mar 07, 2019 at 03:30 AM
I.... I will do some experiment again this weekend before my tech takes it to refurb, I will also use the SX1250 as preamp as you recommended and report back.


@Qguy so I did some experimentation on my units,  my stock SX1250+Spec 4+modded HPM 100 were a good combination and there's a great potential but my re-capped SA 8800ii  + Spec 4 + modded HPM100 combo edged the latter a bit I know it was an unfair comparison though. The SX 1250 was supposed to be restored however I put that aside for now and went with the full restoration of my Spec 4 first (using mattds restoration BOM list at AK).

I am so excited that the restored Spec 4 will be delivered today but since I am in a middle of a move, all my gears are on storage until 3rd week of April. For the test I will use my living room speaker pair TAD TSM300. Due to absence of my gears I got the itch and purchased a Spec 1 in a heartbeat leaving a big hole in my pocket (yikes!) for delivery this Friday (Yay!). Once I'm settled to my new place I will do Spec 1 restoration myself. I will keep you posted on how things goes.

Title: Re: Class A solid state amp who has one?
Post by: qguy on Mar 08, 2019 at 01:09 AM
Guessing the re-capped SA 8800ii  + Spec 4 + modded HPM100 had more detail/definition  vs  stock SX1250+Spec 4+modded HPM 100
Title: Re: Class A solid state amp who has one?
Post by: karipas on Mar 08, 2019 at 05:38 AM
Guessing the re-capped SA 8800ii  + Spec 4 + modded HPM100 had more detail/definition  vs  stock SX1250+Spec 4+modded HPM 100

Hi qguy,
It's not about the details/definition, I felt the SA8800ii combo was much easier (pleasing?) to listen to. I realized my shortcoming on the test was listening to these units not flat; tone controls on and turnovers are at different settings. Note turnover points on these two units are different. The controls were set to where I like them when listening to them as a whole single item and not as just a pre-amp.

The good is I have a bigger playroom on the new place and I can conduct more experiments and comparisons without the neighbor complaining. Stay tuned, more to come.
Title: Re: Class A solid state amp who has one?
Post by: karipas on Aug 22, 2019 at 02:51 AM
Hi, at this point the Class A amp is still a dream :| . I mentioned I will be moving to a new place, after placing all my gears in one location my wife's jaw dropped at the amount of stash I collected and won't even decently fit all in my basement. The High Commander hence put into decree that no spending on any gears at the moment until we finish decorating plus me building a computer desk, audio racks, a kitchen utility table etc; unless I buy these for a ridiculous  amount of money...might as well spend it on the hobby. These will take sometime though. Can be faster if I take a 3 week vacation to finish.  :P
The High Commander also mandated that no audio gear or what so ever will be placed in the family living room :'( , all have to be in my man cave

Here is my plan: build 3 systems + 1

System 1 Family room: All tube + SS : Anthem Pre 1 + Sonic Frontier SFS 80 + SA 8800ii
System 2 Main: Spec 1 + Specs 4 + HPM 100 - up and running
System 3 Garage : Pioneer SX 434 + PSB alpha - up and running
System 4 SX 1250 + Thorens TD 147: Will take a lot of convincing to setup in the living room.

Just to add in my impression on system 2: Spec 1 (stock) and Spec 4 (professionally serviced) are match made in heaven. The Spec 1 is a versatile pre-amp these combo sound great pairing it with any of my speakers. I am already happy with what I have ....plus when I get my hands on that class A, an M-22, a Tannoy, Dynaudio Special 40 ...and...and  >:D >:D >:D

Here is system 2 DIY racks to follow :)

(https://live.staticflickr.com/65535/48596716487_eff12ce0f5_c.jpg) (https://flic.kr/p/2h3jSJc) (https://live.staticflickr.com/65535/48596580086_71aa294042_c.jpg) (https://flic.kr/p/2h3jbbs)
Title: Re: Class A solid state amp who has one?
Post by: alvinbaronsia on Aug 22, 2019 at 05:42 PM
Curious, what made you want an M-22? I do have an M-22, and it is fantastic for small listening rooms.
Title: Re: Class A solid state amp who has one?
Post by: tony on Aug 22, 2019 at 06:35 PM
class A amps are very good sounding, there is no notch distortion, and since the output devices do not traverse a conducting to non conducting state, problems associated with class B operations such as sticking and transitioning distortions are avoided....the price to pay however is the heat cost and the power consumption...
Title: Re: Class A solid state amp who has one?
Post by: karipas on Aug 22, 2019 at 09:12 PM
Curious, what made you want an M-22? I do have an M-22, and it is fantastic for small listening rooms.

Like what Sir Tony said. Also I grew up with the Pioneer brand and began collecting when I started the hobby. Besides the class A sound, you got to admire the unique design and those humongous capacitors. In my listening space I find 10wpc is more than enough so the M22 fits the bill.

There is one beautiful piece on our local marketplace but I have to drive 8hrs to pick it up.
Title: Re: Class A solid state amp who has one?
Post by: tony on Aug 23, 2019 at 07:13 AM
some question the need for high power amps, when all you need is just 5 watts most of the time, indeed an amp rated for 1000 watts will never put out that kind of power playing music no matter how loud you play it, that is because music has far less energy content than the sine wave used to get that spec...

but you will know a high powered amp when you hear it, transients are effortlessly reproduced....
Title: Re: Class A solid state amp who has one?
Post by: karipas on Aug 23, 2019 at 08:46 AM
 ^^^
Sir Tony, you have wealth of knowledge, a true gem to the audio community. I never thought it this way, I  peeked at my power meters as I type while Neil Young's Motor Cycle Mama playing in the background filling the room beautifully. The needles are barely hitting 1 watt at 14 feet distance! I learned something new today :)

^-^
Title: Re: Class A solid state amp who has one?
Post by: tony on Aug 23, 2019 at 08:54 AM
there are lots more to learn if one has the discipline and the drive to gain more knowledge.....

indeed, a powerful amp when run at low power is going to be at its lowest distortion points..

but there is i point where low volumes can reveal hum and noise, but in a very well made amp such as the Pioneers, this is usually no concern...
Title: Re: Class A solid state amp who has one?
Post by: qguy on Aug 23, 2019 at 10:10 PM
I had a Cayin Push pull, Kt88/6550 Class A  amp and the sound was much more sweeter than my Pioneer SX-1250. True enough the heat produced was unbearable in the summer months.  Sold that one a couple of years ago. I recently got a Cayin Class AB EL34 (Stock Tubes) and it is not as sweet sounding as my older Cayin. 

indeed, a powerful amp when run at low power is going to be at its lowest distortion points..

True enough, my 380 WPC power amp  sound a lot cleaner than any of my other amplifiers


but you will know a high powered amp when you hear it, transients are effortlessly reproduced....

correct, even at ridiculous levels,  my high powered amp sounds clean even at the nearfield position
Title: Re: Class A solid state amp who has one?
Post by: karipas on Aug 24, 2019 at 02:36 AM
I had a Cayin Push pull, Kt88/6550 Class A  amp and the sound was much more sweeter than my Pioneer SX-1250. True enough the heat produced was unbearable in the summer months.  Sold that one a couple of years ago. I recently got a Cayin Class AB EL34 (Stock Tubes) and it is not as sweet sounding as my older Cayin. 

True enough, my 380 WPC power amp  sound a lot cleaner than any of my other amplifiers


correct, even at ridiculous levels,  my high powered amp sounds clean even at the nearfield position

You guys are making me defy the High Commander :D :D :D I will get a Class A in my collection eventually :D

@qguy Spec 1 and Spec 4 are a fantastic combo. If you can and happen to come across a pair .... you got to do what you gotta do. Describing or detailing its sonic qualities is redundant and subjective anyways, but this combo is definitely what 70's Pioneer is all about.

If I can compare my gears to a car, my Sansui is prolly a Lexus or the more expensive equivalent, eloquent, sophisticated with finesse so you take care of it, clean it make sure its given the Royal treatment...while the Pioneer is like my WRX rough or edgy, meant to be driven hard and it liked it that way without any worries of breaking any.