The only hafler amps that have the Diablo and Diamond circuits are the Transnova 9505 and the Transnova 9303. The Transnova 9500 and 9300 are very similar to these two amplifers, except for these two circuits.
Because of these circuits, the 9505 and 9303 are better than the 9500 and 9300, but all 4 of these amps are very good sounding amps. They were well worth their retail price in the 1990s when they were made, and since they were made well, they hold up very well - even in 2010. Because of their age, and because many do not know how good they truly are, they can be found very inexpensively on Audiogon and eBay.
In the late 1990's, my brother was blowing woofers regularly in his Celestion SL-700SE Speakers. These were some of the best monitors ever made - about $4,000 a pair in the late 1980's - but they had a very low sensitivity, around 80db. For some reason, his ADCOM 565 Mono Amps could not drive them, so he kept blowing woofers. After blowing his third woofer, I recommended he sell his Adcom amps and buy a Hafler Transnova 9300. He did and heard a huge improvement in sound quality. 11 years later, he still has not blown any other woofers and loves his Hafler amp. Interestingly, the retail price of the ADCOM Mono Amps was more than the Hafler!
These 4 transnova amps were specifically designed by David Hafler and Jim Strickland (of Acoustat) to sound great while driving demanding all speakers, even low impedance speakers. Jim joined David to design these transnova amplifiers because he needed a powerful, good sounding amp that was capable of driving his low impedance elecrostatic speakers. Without an amp like the transnova, he really couldn't sell his speakers to anyone, as there was a market for them without an amp like the transnova. Their design worked very well and received excellent reviews. It was rated Class B and $$$ by Stereophile, meaning they sounded very good and were an excellent value for the dollar. The retail price for the 9300 was $1395.00, the 9500 was $2595.00, and the 9303 and 9505 were a couple fo hundred dollars more than the 9300 and the 9500, respectively. Good luck!
Hifigi (System | Threads | Answers | This Thread)
The Hafler 9505(www.hafler) IS the Trans-Nova, and yes- they all have the DIAMOND driver stage and DIABLO circuitry(see pages 9 and 10 of manual, re: DIABLO): (www.hafler) I've been using one for quite a number of years, to drive my woofer system. Replacing the cheesy RCAs and binding posts, installing IXYS fast/soft recovery bridge rectifiers(www.partsconnexion) and HiFi Tuning fuses at the main and rails, made a world of difference in my unit's presentation.
Rodman99999 (Threads | Answers | This Thread)
Not all of the 9505s had the diablo circuit. Ones made prior to 1995 use the 9500/9300 transconductance stage. These also have a simple J-FET input buffer and the DC servo for offset. Though I can not agree with the statement made about the later diablo models being "better sounding", they are a technically improved design.
Pskaudio (Answers | This Thread)
Hi. I am in the market for a 9505. Can you tell me how to determine when the unit is manufactured? Judging from pics of the rears of several units some are made in the USA and some are made in Mexico. Some have the speaker binding posts at the top while most seem to be at the bottom. So how does one determine the post 95 units? Or which are the more desirable ones?
Nashbap (Answers | This Thread)
I got the Hafler transnova 9303 since 6 month now and i
really love it.It my first power amp as i enter into the audio separate field. The best of this power amp happen
when i get the Meridian 565 in 2 ch analogue, Synergetic
Research IC and Furutech FS ALpha 1 DIY speaker cable.
All up grade produce an audible better sound. But for power
cord the only one i try made nothing so i use with the
Meridian. Since i connected a Sony DVP s 7700 as transport
to the build dac of the Meridian 565, WOW beautiful sound.
I do'nt know the year production of my hafler but i can
said it a great underated power amp i get for $400. used
but mint.I learn a lot by reading audiogon forum but
it really funny to experiment by your self.
Meridian23 (Answers | This Thread)
I just got a Hafler 9505 power amp and it sounds wonderful to me. Very different than my Jolida JD-502P tube amp and IMO a lot better than the Hafler DH-220 and DH500 I had previously. I'm in need of assistance though. Would anyone know where I can get replacement feet for the 9505? I've called Hafler and a couple of the warranty repair centers they mention on their site and they don't have the feet. I also checked some online sellers and they don't have the proper feet either. Any ideas or leads would be appreciated.
Jedinite24 (Threads | Answers | This Thread)