[audiotone]

I have suggested in a few other threads here and at Audiogon that this amp can work with a wide array of speakers. I happen to have speakers with the Lowther DX3 and I can only move my volume knob between 6 o'clock and 8:30. By the time I get to 9 o'clock the volume is way to loud. I think you could easily use this amp with moderately efficient speakers (86-88 db); it is really powerful. I can't speak to the mods you guys are talking about, my gear is stock and I don't know how to do that stuff. I did once put a Prometheus TVC in front of my BYOB and it did give me more range on its volume control. But I was just not comfortable leaving it in the chain.

   

for the high eff speakers there is the low gain version...
I also have the high gain version because I started with the Jordan speakers (88dB), now I am playing with some older stuff...
http://users.pandora.be/tony.de.lobelle/
97 dB when stacked.
I do not like the tvc solution...two resistors 0,1 % would be a technically far better solution IMHO. (to lower the input signal if needed)

[tanchiro58]

I do not like the tvc solution...two resistors 0,1 % would be a technically far better solution IMHO. (to lower the input signal if needed)

Tony,

I have already modified my BYOB amp today by replacing the old stock volume pod with a Goldpoint 100K stepped attenuator. I got an excellent result with a very much better sounding than before. I am able to crank up the volume up to 12 o'clock without distortion (for my ears) and also replace the bypass caps with a Jensen 0.47mF/630V PIO. Now my system sounds very analog just like a tube amp in my second system. I think there is no limitation for either high or low gain BYOB amp. It is depending of all your tweaks or modification. My BYOB amp now does not look like the stock amp anymore and I am planning to put the amp on another extra spruce board with three BRD cones like my Attraction DAC. 

Regards,
Tan

PS: I have also tried to connect Promitheus TVC (two different versions) in between the Attraction DAC and BYOB amp but somehow I did not like that combination's sound at all.

[denjo]

tanchiro58 wrote:

I am planning to put the amp on another extra spruce board with three BRD cones like my Attraction DAC.

Hi Tan
You seem to be having quite a bit of fun with your DAC and BYOB - of course, with the additional help of your solder and deft hands! How do you manage to place BRDs under your Altmann and at the same time keep it from falling down? Do the BRDs actually improve the sound? And how many BRDs?

Many thanks,

Best Regards
Dennis

[tanchiro58]

Dennis,

I bought the Altmann Attraction DAC which is already modified by an expert in medical engineering. He told me the BRD cones help to have more soundstage. I had used so many times the BRD platforms in my system and IMO I do not like the sound at all of the audio components with BRD platforms. But in this case it is totally different ONLY with the right modification. Since I want the BYOB amp to have exact look like the Attraction DAC so why not give a try even though the BYOB amp sounds exactly the way I have expected. There will be only three BRDs (two in front and one in the back under an extra spruce board or plywood). I am not worry the amp will fall down since it is already heavier than before. That is why the reason to keep it more stable on different platform.

This is a lot of fun with this hobby once you can hear an excellent sound out of an already good components.

Tan

[denjo]

Thanks very much for sharing Tan! Your BRD platform sounds very interesting. Care to share a photo of how it looks like? At one time, I was toying with the idea of using a custom made granite platform to hold the Altmann firmly down but felt the sonics might be compromised if granite was used. Your use of spruce ensures that Charles' philosphy of tone control with spruce is maintained throughout.

Best Regards
Dennis

[tanchiro58]

Dennis,

Here are the pictures of my modded Altmann gears:




Tan

[denjo]

Hi Tan

Thanks very much for posting photos of your custom made platforms! Very nice indeed! I agree with you that using anything else than spruce might alter the tonal balance of the Altmann and BYOB. Are those ebony black discs? You have at least 3 different variations.

Best Regards
Dennis

[tanchiro58]

Are those ebony black discs? You have at least 3 different variations.

Dennis,

Thanks for your kind words. Those are Shun-Mook discs and variable sizes of DH cones. Somehow when I put these discs on both Attraction DAC and BYOB amp's spruce board the sound gets more mellow.

Tan

[rodge827]

Tan,

Great pics  !!! Your set up and workmanship are first class fore sure  !!! You mentioned that your amp is the high gain version. Did installing the attenuator help for the use in your high sensitvity horns ? What attenuator did you use ? I'm looking to purchase a pair of high sensitivity speakers in the near future and was wondering which amp I should settle on.

Rodge

[tanchiro58]

Tan,

Great pics  !!! Your set up and workmanship are first class fore sure  !!! You mentioned that your amp is the high gain version. Did installing the attenuator help for the use in your high sensitvity horns ? What attenuator did you use ? I'm looking to purchase a pair of high sensitivity speakers in the near future and was wondering which amp I should settle on.

Rodge

Rodge,

Thanks for your kind words. My horn-based speakers are custombuilt by my friend. Since I replaced the stock volume pod with a Goldpoint 24 steps attenuators 100K mini V model (using Vishay resistors) the loudness is totally disappeared with more musicality. I am looking for a pair of high efficient speakers too for my second set up in the living room and I see Zu Druid IV is my first choice. I am using the modded Altmann BYOB amp and the combination of Altmann has changed my thought about solid state amplifiers which I never liked the analytical sound of it. Actually the BYOB amp was sounding analytically before the modification too but now it has the bloom and sweetness of tube in high and midrange and the punchiness and body of solid state in bottom (deep tight bass). 

Tan