The new Harmonia v4 - 45, 2A3, 300B output stage for source components

Response Audio · October 11, 2025, 03:01:31 PM

Introducing the new Harmonia V4. The v4 is designed as a DHT output stage for your DAC, CD player, etc. The v4 can accommodate the 45, 2A3 and 300B with the only adjustment needed by the user is the filament voltage that ranges from 2.5V to 5V. An internally mounted LED meter allows you to quickly make the change.
Using the Harmonia after a DAC or CD player provides you with the seductive SET sound for all your source components.
Not a cathode follower 'buffer' stage rather a true anode follower allying you to experience the full sound of the tube.

https://responseaudiony.com/harmonia-v3-1

Nick B · October 11, 2025, 08:55:38 PM

Simple and stylish and adjustable as well. Nice design, Bill. What type tubes are those?

Nick

Response Audio · October 12, 2025, 10:18:17 AM

Thanks Nick. This last piece will be custom built to order allowing the buyer to customize.
The tubes in the top picture are Sophia Electric 300Bs. Bad tubes installed for photo.
In my personal unit, set up as a preamp as well, I run either Sovtek 2A3, Valve Art 300B (my favorite) or NOS RCA 45's.

Response Audio · October 22, 2025, 01:28:02 PM

The new Harmonia v4 & Harmonia Jr.

https://responseaudiony.com/harmonia-v3-1

Response Audio · October 26, 2025, 09:24:03 AM

The v4 above has been sold. New 2026 chassis now in development.
We have multiple Harmonia Jr chassis in stock ready for your custom build.

Nick B · October 28, 2025, 12:39:49 AM

Quote from: Response Audio on October 26, 2025, 09:24:03 AMThe v4 above has been sold. New 2026 chassis now in development.
We have multiple Harmonia Jr chassis in stock ready for your custom build.

That's great, Bill. Pls provide pics when that 2026 chassis is done.
Nick

Response Audio · October 30, 2025, 10:47:38 AM

Will do Nick. We are developing more universal chassis as we go further into our custom preamps.
I have full intentions on bringing back a new, enhanced version of the Purity Audio Design Reference preamp circuit. The Reference has long been our most popular and well received/reviewed preamp. This will fall into our upper level products.
We have a scaled down version that is available in the Spirito/Harmonia Jr chassis for those who want a top line 6SN7 linestage without bells and whistles. Just pure sonic heaven.
In fact, was just listening to the last custom unit last night! This is a full Reference with 5U4 power supply driving our MB2A3-SE amplifier.

Quote from: Nick B on October 28, 2025, 12:39:49 AM
Quote from: Response Audio on October 26, 2025, 09:24:03 AMThe v4 above has been sold. New 2026 chassis now in development.
We have multiple Harmonia Jr chassis in stock ready for your custom build.

That's great, Bill. Pls provide pics when that 2026 chassis is done.
Nick

Nick B · October 31, 2025, 09:55:33 AM

Quote from: Response Audio on October 30, 2025, 10:47:38 AMWill do Nick. We are developing more universal chassis as we go further into our custom preamps.
I have full intentions on bringing back a new, enhanced version of the Purity Audio Design Reference preamp circuit. The Reference has long been our most popular and well received/reviewed preamp. This will fall into our upper level products.
We have a scaled down version that is available in the Spirito/Harmonia Jr chassis for those who want a top line 6SN7 linestage without bells and whistles. Just pure sonic heaven.
In fact, was just listening to the last custom unit last night! This is a full Reference with 5U4 power supply driving our MB2A3-SE amplifier.

Quote from: Nick B on October 28, 2025, 12:39:49 AM
Quote from: Response Audio on October 26, 2025, 09:24:03 AMThe v4 above has been sold. New 2026 chassis now in development.
We have multiple Harmonia Jr chassis in stock ready for your custom build.

That's great, Bill. Pls provide pics when that 2026 chassis is done.
Nick

Thanks, Bill . Very nice looking chassis on your preamp. A good idea regarding a universal/multi use chassis.