DjOverdose

its powering a pair of RP280F.

just want to uodate this thread... got my 2a3 amp already and boy it does not disappoint! now i know what it sounds like when they say youll be surprised what a few watts can do. its still in the break in period but it sound good already. though the bloom is still not there but the voice... the voice.... its like they are just right in front of you. comparing it with my kt120 amp, the kt120 feels like its too excited to show off but your trying to hold it down. the highs sometimes goes too high but the lows and the thump are really there. while the 2a3 is like the guy in your neighborhood who takes his time walking like his not in a hurry and appreciates everything he see's around him. everything seems to he balanced listening to the 2a3. its so quite that theres very little to no hum at all. the details and nuances are more pronounced in tye 2a3 amp. probably it is because of the sensitivty of the speakers as well. its easy to be driven thats why when im using the kt120, the hum is more evident compared to the 2a3. also the kt120 is much louder its like even playing at the same volume level, the kt120 feels like its shouting while the 2a3 is just telling you a good story. Its not a night a day difference but the 2a3 is just dead silent and clean. what more if its totally broken in. maybe if i pair the kt120 with a speaker that has an 85db or 87db probably it will sound much better since itll be flexing its muscles to move those woofers in and out... I will be replacing the 6n3c with kt66 and the 5u4gb with 274b and hope they will sound nicer. thanks guys for all the replies....

noted on this... will ask the builder what those tubes are for. really have no idea.... 😁

just want to share the whole amp set up... in the middle is my kt120 PP then on the left is the PSU of my Phono/line pre amp. (right) i had requested to have my pre amp to have to outputs so that when the time comes that I will have 2 power amps either a SET or an SS, it will be easier for me to switch. tubes used in the power amps are kt120s, 12at7, and ecc99. while for the pre amp PSU, regulator(?) was a 274b or 5u4g the n rectifier was el34. can also use either 6v6, 6ca7. for the phono/line all tubes are 12ax7.

the tube in the middle was a 6n3c. i think he used that as a rectifier tube?

err... to be honest when he was explaining the switches and selector to me, I just nodded. hahaha o really cant remember which is which. all i can remeber is that the one at the back is the voltage selector for a certain tupe of power tube. the other switcj is for the filament. the 3rd i need to change the bias every time i change to a different power tube... at this point i dont know if i can still use my kt120 power amp or if i will still be switching to it.

I had the opportunity to take her home when i took this pictures. however the cage was not yet finished. so i decided not to bring her home not until the tube cage is finished. I have kids in the house, though im not concern about them having burns since i always listen at night. but im afraid that they might hit the tubes with a rubber ball when they are playing. hahaja that would be a bummer. thank you... itll take quite awhile. need to brake in the power tubes and the opt...

Yup it does have alot of iron. He builds the whole OPT and chokes from scratch so that he can customize the amp depending on the clients specification or request. the 9 pin is a 12at7. it drives the 5u4gb for the 2a3 power tubes.. the the middle one is a rectifier tube. forgot the tyoe though.

Hello. Yes he placed a switch at the back of the amp. If i remember it xorrectly it has 4 modes. thats for the voltage selector. 1st is 5V for the 300b and JJ2a3 40w 2nd is 4.5 and 3rd is 4V these are for the normal 2a3. then 4th was like 3.5v? cant remember actually the volatge. he just explained to me that the latter one is for the 45 since its the lowest voltage. so i can use option 1 to 3 for the 2a3. just obeserve which amongst it will sound sweet to my ears. Also if youll check the first picture, youll notice at the back of the 2a3 tubes theres a label that says 2a3. thats actually the filament switch? for 2a3 and 300b. as for the 45, ill just use the 2a3 and then set the correct bias. theres alot of things to fiddle with this amp. requesting the builder to give me a manual because i might forget about it after awhile. it also has a hum balancer on top and a gain controller at the back.

almost done. just waiting for the cage to be finished. the builder say its somewhere around 3.5WPC to 4WPC.

nope... thats the model of the tubes. JJ 2a3 40W

Hi Garyrc! i really dont know the exact size of the area. its a mix used room though, dinning, living room etc. i listen probably around 2M away from the speakers. Due to the limited space i have, my speakers are almost close to the wall. after reading your reply, I guess the 2A3 amp will be fine on powering the RP280f. hopefully My amp will be finished this week

hey jeff. thanks for the input. i have no ideawhat wires his using inside the amp. im using a QED XT silver anniv as my speaker wire. i wonder what the speaker will sound like and using a copper one. i cant do anything About the toggle switch since it was alrradu6 thetr.

nope... thats the model of the power tubes.

almost there... according to the builder, he is just finishing the wirings.... hipefully early next week... 2pcs jj 2A3 40w 2pcs 5u4g 2pcs 12at7 1pc 6n3c switchable 300b and 45 with hum and gain control. cant wait to hear it play.

he does make his own output transformers. back here in Manila Philippines there are two local tube amp builders, Rene Rivo of Music haven and Andrew Sevilla of AMX audio. both of them can make custom amps depending on your requirements or specification.

yes. thats what my plans are right now... i might just keep the kt120s. I will just going to put an A/B swith for my speakers. I had my custom preamps have 2 outputs specifically for putting 2 different amps.

ill be having it on a single chasis. another local builder told me that there is little difference from the mono blocks and single chasis. but cost wise theres alot. Heres the chasis of my 2a3 amp. itll be powered by a pair of jj2a3 40 rectified by 5u4gb tubes. i forgot the other tubes that will be put in.

will update you guys once the amp is here. im very very excited...

i only have a small space for the speakers though. ive read somewhere that the reference are not that sensitive as advertised. since its a custom amp, i can have an option to switch from 2a3 to 300b with a togfle switch and from 2a3 to 45 by just adjusting the bias...

Hello... thanks for all the replies.... i just gave the go signal to my local amp builder to build me a SET 2A3. i am hoping that the 2A3 can power my RP280F. its 98db sensitivity. i decided to keep my kt120 for versatility.

Hi Again. I would like to ask your opinion on this. Currently I have a custom made Tube Pre amp and power amp. Power amp is a KT120 rated at roughly around 80WPC its powering my Klipsch RP 280F. I know its waaayyy to much for the speakers though they sound really good. however curiosity strikes again and was thinking if a 2A3 power Tube can power these Floorstanders. I know they are 98dB but is it enough for a 3-3.5W power amp? anyone tried this combo?

Wow.... thanks for the very positive response..... looks like my daughter will have no allowance for a few weeks.... hahaha just kidding. Will check on that audyssey app you mentioned. I guess Im good and all set. thank you very much! Big help! PS: Its really a good thing that despite the advent of Facebook, Forums like this still exist. you can never replace the information you get from forum based groups...