The Grado GS1000 (Classic) is 38Ω at 99.8 dB/mW; the Grado Signature S750 is 38Ω at 115.0 dB/mW. This page covers what they ask of an amplifier, not how they sound.
The GS1000 (Classic) needs 15.2 dB more than the Signature S750 to reach the same loudness — 1.0 mW against 0.03 mW.
| Specification | GS1000 (Classic) | Signature S750 |
|---|---|---|
| Impedance | 38 Ω | 38 Ω |
| Sensitivity | 99.8 dB/mW | 115.0 dB/mW |
| Sensitivity (voltage) | 114.0 dB/V | 129.2 dB/V |
| Power for 100 dB | 1.0 mW | 0.03 mW |
| Voltage for 100 dB | 0.20 V | 35 mV |
| Current for 100 dB | 5.2 mA | 0.9 mA |
| Highest source impedance that leaves them alone (one-eighth rule) | 4.75 Ω | 4.75 Ω |
| Sources that reach 100 dB out of 280 | 280 | 280 |
Every source in the database that drives one of them drives the other. On power, the choice between these two changes nothing about what amplifier you need.
21 sources stay below the audible-hiss threshold with the GS1000 (Classic) but cross it with the Signature S750 (FiiO BTR11, Fosi Audio SK02, FiiO K11 R2R, 18 more).
280 of the 280 sources here reach 100 dB on both.
The GS1000 (Classic) is more demanding than 58% of the 567 non-electrostatic models in this database; the Signature S750 than 4%.
| dB SPL | GS1000 (Classic) power | GS1000 (Classic) voltage | Signature S750 power | Signature S750 voltage |
|---|---|---|---|---|
| 80 | 0.01 mW | 20 mV | 0.3 µW | 3 mV |
| 85 | 0.03 mW | 35 mV | 1.0 µW | 6 mV |
| 90 | 0.10 mW | 63 mV | 3.2 µW | 11 mV |
| 95 | 0.33 mW | 0.11 V | 0.01 mW | 19 mV |
| 100 | 1.0 mW | 0.20 V | 0.03 mW | 35 mV |
| 105 | 3.3 mW | 0.35 V | 0.10 mW | 62 mV |
| Source | Price | Headroom, GS1000 (Classic) | Headroom, Signature S750 | Output impedance | Noise |
|---|---|---|---|---|---|
| JadeAudio JA11 | $20 | 13.8 dB | 29.0 dB | 0.5 Ω | 1.7 µV |
| FiiO KA11 | $29 | 22.1 dB | 37.3 dB | 0.7 Ω | 1.7 µV |
| FiiO BTR13 | $59 | 19.0 dB | 34.2 dB | 0.6 Ω | 1.0 µV |
Of the 280 sources here, 280 reach 100 dB on both. 51 of them also publish an output impedance low enough for both under the one-eighth rule and a noise figure that stays below the audible-hiss threshold with both.
The cheapest of the 51 is the JadeAudio JA11, at $20. It leaves 13.8 dB of headroom on the GS1000 (Classic) and 29.0 dB on the Signature S750, its output impedance is 0.5 Ω against a one-eighth limit of 4.75 Ω for both, and its noise figure puts the hiss floor 21 dB and 6 dB below the 20 dB SPL this site treats as the point where a quiet room stops hiding it.
| Model | As printed | Tolerance | Standard |
|---|---|---|---|
| GS1000 (Classic) | 8-35 | not printed | not printed |
| Signature S750 | 4Hz – 48kHz | not printed | not printed |
Grado prints 8-35 for the GS1000 (Classic) and 4Hz – 48kHz for the Signature S750.
Neither range has a tolerance printed beside it, so a wider range on one sheet is not deeper bass or more treble.
Not a measurement; maker by maker.
Both have a page of their own. In full: Grado GS1000 (Classic) and Grado Signature S750. Every figure on this page comes from what Grado published, or is derived from it — what that maker publishes, counted.