Search results

If you are willing to upgrade the op amps, you’ll find that the Fosi ZA3 amps will work very well for driving your LaScala clones full frequency. As monoblocs, the power output does not double as the TI TPA3255 Class D ICs are already operating in Bridge Tied Load (BTL) mode. Running the amps in...

I have a Denafrips Pontus II and recently bought a Denafrips Ares 12th-1. If you want an organic, analog-type presentation, I would recommend an R2R DAC like the Denafrips DACs mentioned. Denafrips offers firmware updates, but I haven’t tried them, because they sound excellent as-is. For...

That giant power amp is a Pass DIY Aleph J Class A JFET/MOSFET amplifier that I built myself using schematics, printed circuit boards and 4U chassis from diyAudio.com’s online store. It has both balanced XLR and single ended RCA connectors. To my ears, many of Nelson Pass’ Class A solid state...

No problem. In re-reading this thread, jheu02 referred to a Fosi Audio BT20 amp, not the Fosi Audio ZA3 amp, as having the Beryl capacitors. I was able to use both my ZA3 amp and the other ZA3 amp as dual monoblocs using XLR balanced connections. This setup driven by my Schiit Freya+ tube line...

A member of another audio forum had contacted me and asked if I would be willing to install a pair of MUSES02 op amps in a Fosi ZA3 amp he purchased through the latest production round that shipped at the end of January. He had it drop shipped to me along with a pair of the MUSES02 op amps. I...

I looked at a photo I took of the Fosi Audio ZA3 internal PCB and components when I changed op amps. I don’t see any op amps labeled as “RCA” op amps. There is a single op amp labeled as “XLR.” I changed the op amps labeled as “L-OP AMP” and “R-OP AMP” adjacent to the volume control-power...

That is true “bargain” hifi, and I’m sure that extra gain from the tube preamp makes for a richer sound quality.

Thanks, based on what you’ve shared, you should be fine with substituting the F2 clone with the Fosi V3 or the Fosi ZA3. I have an Aiyima A04 Class D amp that I modified, and with using the Fosi ZA3 and rolling op amps, it is my opinion that the Fosi amp is better constructed than the Aiyima...

in your arrangement, what are the speaker loads you are driving with the F2 amps? Nelson Pass has a list of his First Watt amp designs with information on output impedance and output at different speaker load impedances, so you can determine if the ZA3 will work in your arrangement.

As much as I enjoy the Fosi ZA3 and all the fun that comes with trying different op amps, the experience of listening to amplifiers like a First Watt Class A amplifier or to a classic McIntosh tube amplifier is worth pursuing. These amps, among others, take music listening to another level. I...

If you can take advantage of the Fosi zA3’s XLR balanced outputs with whatever DAC you purchase, you should be good. Although balanced connections don’t guarantee the best sound possible, most DACs costing less than $800 with both balanced and single-ended connections tend to have better...

There is an op amp used with the balanced XLR connectors, another two op amps for the TPA3255 IC amp inputs and another two op amps for the subwoofer outputs. I would focus on the two op amps for the TPA3255 IC amp inputs for op amp swapping. Consider only dual op amps that are suitable...

I had ordered a couple pairs of op amps from Fosi Audio to try out in the ZA3: Nisshinbo MUSES02 Burr Brown OPA2134 After managing to open up the chassis, I noted the orientation of the stock TI NE5532 op amps at the TPA3255 Class D amp's inputs. There is a small indented circle marker on...

That's a good question since Texas Instruments focused on measurements at 2, 4 and 8 ohms speaker impedance when they released the TPA3255 Class D amplifier. It should be fine, but if you want to try the Fosi ZA3, wait until Amazon re-stocks these amplifiers so if it doesn't work well, you can...

A friend recommended leaving the ZA3 powered on, so I left it on all night with the volume turned all the way down. When I spun some vinyl today, I was really impressed with the scale of the soundstage compared to what I heard yesterday. The music has a really solid foundation in terms of...

I ordered a Fosi ZA3 from Amazon this past Wednesday and it arrived yesterday morning. Upon unboxing the nicely packed amp and 48V-5A power supply, both pieces were ice cold, so I had to allow for everything to warm up to room temperature before powering anything on. I connected the ZA3...

I have the Aiyima A04 which is very similar to the Aiyima A07, except it is based on the Texas Instruments TPA3251 Class D IC instead of the TI TPA3255 IC. They are similar in sound quality—both very good for the money. Besides being very affordable, these Aiyima amps can be tweaked with...

I live part time in Minneapolis, MN, and I really miss Jerry Raskin’s Needle Doctor in Saint Louis Park, MN. They were a brick and mortar shop with an excellent mail order/Internet sales channel with great customer service. The shop has since been taken over by a really nice record store, Solsta...

I subscribe to the Darko Audio channel on YouTube and I generally agree with what he shares in his reviews and commentary. Based on that video review, I seriously considered getting the Pro-Ject Debut Pro over the Technics SL-1200GR (his is a Technics SL-1210GR), but I could not beat the allure...

I recently purchased a Technics SL-1200GR, and I am very pleased with it. The sound quality surpasses my original expectations for a mid-high end turntable and I can be quite satisfied for a long time. I have read many audio forum posts where many have dismissed the SL-1200GR’s arm, but when...

I've had a Freya + now for almost two weeks now, and I am very impressed with this amp. I have only listened to the Freya + in the JFET differential buffer mode and in the tube differential mode. In my opinion, both modes sound great with my preference for the tube mode when I am actively...

The Audio Society of Minnesota has monthly virtual meetings on Zoom. Before the pandemic, ASM met at the Pavek Museum in Saint Louis Park. I don’t live in the metro anymore, but I still participate in the monthly Zoom meetings when I can. The group is a good mix of music lovers, local audio...

I recently completed a DIY build of the Aleph J amp, and I’ve been playing it for about two weeks comparing it to my other amplifiers: Dynakit Stereo 35 with EFB mod Pass DIY Sony VFET Class A McIntosh MC240 I expected a nice Class A SS amp when I built this, and one of my primary motives was...

I obtained a pair I the Burson Audio V5i-D dual op amps through Mass Drop offering them for $42. I am extremely satisfied with the Burson op amps. Many people have had positive things to say about the OPA1656 op amps on DIP8 adapters. They were nice, but I like the Bursons.

gasolin75, To answer your question, you should consider the following for each amplifier: distortion vs. power curves for the nominal impedance closest to your speakers’ impedance, and efficiencies. I prefer the Texas Instruments TPA325x Class D amps. I really enjoy the Aiyima A04 TPA3251 for a...