justinsweber

Ive grown to appreciate pull designs more and more. SET amps (forgive the implication) are like a C*ck tease. All the tone/sound you could ask, but never enough of it. Well designed SET amps can be just as quite as any other design, its the lack of significant horsepower that becomes a consideration. If in a small room or not trying to see how loudly you can play, SET amps are incredibly pleasing. But, a P-P amp has some feedback which will provide its own benefits. All the sonic benefits you find tubes in general are offered in great abundance with P-P designs. Im not a fan of Parallel Push Pull or Parallel SET but there are reasons for that... Ill leave it at the KISS approach as rule outs. Class A SS badass. SET Badass but not enough for most of us. P-P Tube... just right. (Dynaco ST35/ ST70, Rogue Chronus, MC275, nearly any KT88 P-P or EL84 P-P )

Different amimals all together. Though I respect pass designs. I’m decidedly a tube guy. Sold guys

Donating these to my daughters school. Need a pair or scalas for refurb. Thanks justin 323-868-9722

Selling off an early prototype of the Agartha. Bases on the the GSE from DIYaudio. 6B4Gs for output tubes, 6AX5 rectifier and 6SL6 front end. All NOS, ALL US tubes. Includes functioning VU matters. 5watts SE tube goodness. Price is firm. Justin 323-868-9722

Sansui AU717 :-).

bump

Massdrop is great but delayed gratification for sure.

Parks Audio - Budgie MC Cartridge Step Up Transformer . Transformers made by CineMag CMQEE-3440AH and are simular to Bob's Devices units at a much lower price. The Budgie Step Up Transformer (SUT) now showcases the fantastic Cinemag CMQEE-3440AH transformer. These transformers are constructed with superior laminations that Cinemag has reserved over the years for devices requiring the lowest distortion and highest clarity. In fact these are the same laminations that are used in the top of the line CM1254 and CM1131 transformers. It has two gain settings and a ground lift switch for maximum flexibility. 3440AH is basically the 3440A built with better laminations. The sound from the Blue version is a step above the Red version. Switchable for 1:16 (24 dB gain) or 1:30 (30 dB gain). Into a standard 47k phono preamp, the effective input impedance of the low gain (1:16 ratio) is 184 ohms. At 1:30, the effective input impedance is 52 ohms. Justin 323-868-9722 $360 with shipping.

This looks interesting too. http://r.ebay.com/lM5Phs

Just for clarification. I went to the linear PS due to noise/output issues. The SMPS was sooooooooo noisy the amp was unable to reach full power. On my Bench supply it worked perfectly. The Linear supply at 19V or 24V will achieve the same result. Many previous ACA kits swapped in the 24V SMPS... prob performed better. All that said, I think its a great kit. If one is willing to upgrade to a linear supply they will get a Pass reference level amp for peanuts.

Nice! Hows the bass?

98db 15c minus 108.5 B&C dcm50 = gets us to 10.5. I pulled it down to -12 to get better integration. 98 + 3db being horn loaded or so. 101db as a realistic starting point. 101-108.5=7.5 if it were me. I’d try 8db, 9db and 10db to see how thing sound.

15c in a Cornwall style cab.

I ran mine at -12db down. Sounded amazing.

It works ok. The panels were not at tight as Id like. I ended up added L-Brackets to make the unit stronger... Maybe Im just nit picking.

http://r.ebay.com/qX4NCM http://r.ebay.com/RWQeLJ http://r.ebay.com/Q4vuOs http://r.ebay.com/mrCEtE http://r.ebay.com/lkU0CB http://r.ebay.com/yjzQDM http://r.ebay.com/y6f9Q3 http://r.ebay.com/zJUbBL http://r.ebay.com/HIn13Z http://r.ebay.com/RN76dr http://r.ebay.com/PjJszK

Does the M2 use an Opp amp? I thought I eyeballed on in a pic?

Is there a version of the M2 not using edcor iron?

Short answer... no. Most look like lab equipment. There are some Jeff Roland clone chassis around... those look amazing.

The M2s I've seen used Encore transformers. Ive had a been time with time more than once... its a non starter for me. Ive heard my fair share of pass amps... I put the ACA and the F6 and Alph right up there. I went F6 for use use of input transformers. If selecting Firstwatt DIY projects, Id always recommend ones without feedback as they are a more forgiving sound :-).

The true F6 casework/ first watt casework is much better than the DIY stuff.

The ACA was a ton of fun to build.

The MC252 is a real monster... wish I had one. I had that servicing it is beyond my skill. The F6 is completely serviceable. I do wish I had made mono blocks but such as life.

I would suggest not doing ACA kits unless doing regulated power supplies. Ebay has many good options. The stock ACA is noisy/ bad but is a great starter kit. To turn it into a reference level amp it needs the power supplies. With the power supplies, its a class winner just lower in output.

I’ll half to revisit my notes. I think the orientation of the jfets was backwards. But I’ll check my. It’s next week. I did the pre drilled chassis too. It didn’t line up so well. We used l-brackets to get everything snugged up and square. Id love to know the differences between the f6 and m2. I went f6 as I had heard Dave Harris and loved. Also the use of input transformers was right up my alley.