


🎧 Tune into precision — don’t let your sound system settle for less!
The TOA ZM-104A Impedance Meter is a professional-grade tool designed to measure speaker line impedance up to 100k ohms with ±10% accuracy. Featuring zero adjustment for enhanced precision and a direct-reading meter calibrated in ohms, it simplifies audio diagnostics. This durable, battery-powered device includes test leads, a carrying case, and an impedance-to-power conversion chart, making it an essential instrument for sound engineers and audio professionals.
| ASIN | B004KO1AS8 |
| Batteries | 4 AA batteries required. (included) |
| Batteries Included? | Yes |
| Batteries Required? | Yes |
| Battery Cell Type | Alkaline |
| Best Sellers Rank | #231,045 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #99 in Sound & Noise Meters |
| Brand | TOA |
| Color | Black |
| Customer Reviews | 4.0 4.0 out of 5 stars (19) |
| Date First Available | November 20, 2007 |
| Is Discontinued By Manufacturer | No |
| Item Package Quantity | 1 |
| Item Weight | 1.54 pounds |
| Item dimensions L x W x H | 10 x 6 x 3 inches |
| Item model number | ZM-104A |
| Lower Temperature Rating | 23 Degrees Celsius |
| Manufacturer | TOA Electronics |
| Measurement Type | Ohmmeter |
| Min. Operating Voltage | 6 Volts |
| Part Number | ZM-104A |
| Power Source | Battery Powered |
| Product Dimensions | 10 x 6 x 3 inches |
| Specification Met | Cat I |
| Style | Modern |
| Upper Temperature Rating | 104 Degrees Fahrenheit |
K**H
A longtime high quality meter
My opinion as an audio service professional for 30+ years with a major national company, this is the best impedance meter ever made. Simple to use with accurate results. And totally repairable by TOA if you happen break it. If you’re gonna buy an Impedance Meter spend a few extra dollars and buy this one. The only little complaint I do have, plastic the “hinge” wears out on the front cover. Mine has small metal hinges riveted in place now, but you can easily buy a new case if your desire.
R**G
Five Stars
I install commercial sound systems for a living, and this is a tool I can't live without.
E**I
DOA, will return for refund
Arrived DOA. Packaging was in good shape but meter not work. Will be returning for a refund.
P**R
I’m hopeful
I first purchased this earlier last month. But that on arrived dead. I spoke with the manufacturer about it and after our discussion they determined it was a dead piece. They asked me to return it to the seller and request a new one. So I did and it took a month to receive it. Not sure why it was supposed to be an equal exchange. I did not get any emails from them. But it arrived today I will update on if this one works properly.
A**R
My other right arm...
I have used versions of this meter since 1986. I've worn out two over all that time and now it's time for another one. It may not be high-tech but it does a fantastic job. It works especially well reading actual impedance through a Transformer setup. The tone it generates also is helpful in locating hidden speaker devices. At the price it sell for here on Amazon, the one I'm getting is costing the same as the one I last purchased back in 1993 so I consider it a good deal.
K**R
The only one
25 years in commercial sound, used the Raymer bridge which was OK but unreliable. THen I got the TOA. Any tech worth his salt should own one of these. Durable, accurate, wide range, simple. I bought a second one as a back up they are so versatile. I think mine were 102s and came with a schematic, a few transistors and resistors damn, you cant beat a good design(r)
C**.
I love this bridge
Brand new and works great! I love this bridge!
J**W
needle was stuck and it never worked. sent it back
it did not work. needle was stuck.
Trustpilot
1 month ago
2 weeks ago