By Xin Feng 05/30/02
You can buy some of these radios (modified or not) on the Cool Stuff page.
"The world's best audio bargain" - Neil Stebbins, in his Stebbins' Stage column regarding our modified radios, published in Volume15, #2 2003 of The Inner Ear Report magazine.
[08/20/03] After more examination, the M37 is not as good as SRF-S84 and M35 on sound and reception and, too bad, there is no easy fix. The problem is in the IF area, which is hard to be modified. Therefore, we won't sell M37.
[04/30/03] The new Sony SRF-M37V. Obviously this is the replacement of the SRF-M35, but it is entirely re-designed, inside and outside. First of all, that dreaded background noise found in M35 is totally gone and M37 now sounds deadly quiet like SRF-59, -S83 and S84. It now uses only one AAA battery which lasts 34 hours for FM and 54 for AM. It sounds quite good right out of box and I noticed 470uF caps (vs. 220uF in M35) - Sony engineers have read this website and agreed with me!
Reception seems close to M35. Looks much better than the dumb M35 and now there is even a battery indicator. However, still no sleep timer. Too bad. Two good things added are TV and WB. TV reception is very good and I can get all the UHF channels, clear and loud. It still gets no weather station though. Actually I've never get WB with any radio. You can purchase this new Sony from our Cool Stuff page. When I have more time, I'll look into it and see if there is still something left for me to improve.
Here is the original article
Father's Day is right at the corner (June 15). Believe me, a decent pocket radio is welcome to every father. Choosing the right one is a difficult job though, but this page will help you out (or add even more confusion, indeed).
First, the showdown is between Sony and Sangean. Why? Because radios sold under different brand names such as Aiwa, RadioShack, Roberts, Sharper Image, etc., are actually all made by Sangean.
Second, Sangean is second to Sony on pocket radios. This is my opinion and your mileage may vary. Sony owns the best radio ICs, such as the CXA1129 (1.5V FM/AM), CXA1238 (3V FM/AM), 4535/4537 (1.5V amp) and 4533 (3V amp) and Sony does not sell them to OEMs.
Now let's look into Sony pocket radios.
From left to right, they are SRF-59, SRF-M35, SRF-S83 and SRF-M95.
SRF-59 This one is relatively the largest in size, but still very compact and portable. Because it uses the same excellent FM/AM IC (CXA1129) used in SRF-S83 and has plenty room inside, it is the most modifiable pocket radio for those seeking for the best sound. See my SRF-59 tip for how to modify it or buy one modified on our products page. After the mods, it punches with full energy!
SRF-59 uses just one AA battery, which lasts for months for regular use. I use a 1600mAh rechargeable Ni-MH battery and get at least a week play (more than 12 hours listening per day). Its belt-clip is very well designed and very secure. Easy to operate too, if you belt it in the way as showing in the photo.
SRF-M35 If you have to have a digital tuner, this is the one. About a year ago, I tried a SRF-M35, or could be the SRF-M32, its predecessor, and dropped my interest because of the background noise problem. Thank to Mike Walker from head-fi.org for his firm recommendation, I decided to give it one more try. Mike was right, either Sony have minimized that noise to acceptable level or the specific one I tried before was defective. After opening the M35 I bought recently, I saw two 22K resistors (one per channel) between the output of potentiometer and the input of 4533 (amp). These two resistors must be low-noisy type and not too large, or the noise they generate will be amplified by the amp and becomes audible even you turn the volume all way down. The noise they generate is different than normal amp noise and its level does not change via volume. Also missing are two filtering capacitors (should be 100-300pf) at the amp's inputs. This may add noise too, but also contributes to M35's openness and brightness.
M35 is as sensitive as SRF-59, but sounds better right out of the box due to its larger output capacitors (100uf vs. 47), lower selectivity and correct de-emphasis capacitors. However, it still sounds slightly thinner and not so punching than a modified SRF-59. It uses 3-volt ICs, a CXA1238 FM/AM and a 4533 10-pin amp; that's why it has to use two batteries (AAA) instead of one. What you get is significantly higher output volume. For a pocket radio with a digital tuner, what's missing in M35 is an auto-shutoff timer, but its battery life is excellent though, 30 hours for FM and 40 for AM.
Wow, what a huuuge sound after the mods! I replaced the two 100uf output capacitors with 220uf ones, the two 2.2uf input capacitors with 47uf ones, the 220uf power filter with a 330uf one and the 10uf capacitor of 4533 with a 100uf one. This radio now sounds truly vivid, articulate and punchy. The best experience with a bare portable so far; more open, dynamic and faster than a modified SRF-59. Now I hear the tails of a triangle or a bass string. The DT-110 is simply no compare.
With such a good sounding portable radio, you have no more excuse to carry a bulky CD player and/or a headphone amp.
SRF-S83 (now SRF-S84) If you want the smallest size and the best sounding and reception, this is the one. It uses the same CXA1129 IC used in SRF-59 and uses only 1 AAA battery to operate. Right out of the box, it sounds almost the same as SRF-M35 but slightly darker. After my modification, it has more extended bass and dynamic range. Its belt-clip is not so secure and you should make a little adjustment before it's too late (see my SRF-S83 tip for detail). It is not significantly more sensitive than SRF-59, -M35 and M95, but I've not seen anything that has a better reception neither. SRF-S83 features a bass boost IC (LA3550) and the effect is excellent - bass goes very deep while leaving treble untouched. Overall, this is the best pocket radio that we recommend, not just for its smallest size, but for its sounding and reception as well. The modified M35 has slightly better treble, but S84's deadly quiet background weighs out M35.
SRF-M95 If you want the smallest size and meanwhile a digital tuner and you've got lots of money in your pocket, this is the one. Its sound character is totally different than above ones - it sounds "digital", very much like a portable CD or MD player. Due to its very special design and the ICs used - no any electrolytic capacitors inside, it seems non-modifiable, at least so far. While the other modified Sony radios we introduced above all have the non-fatiguing, warm and rich sound that's not found in any portable CD or MD players, this M95 sounds very much like a CD - no distortion, no noise and excellent channel separation; treble and bass are all there but no punching nor energy neither. Simply put, there is no something called music from it. SRF-M95 also features a bass boost switch but the effect is not as good as that of SRF-S83 - bass goes too loud to keep treble untouched.
Two Alternatives If you don't like Sony, or for whatever reason, you might give the Aiwa CR-LD120 (very similar to SRF-M95) or Sangean DT-110 (similar to SRF-M35) a try. Both are less sensitive and have shorter battery life than the Sony rivals. The CR-LD120 has the same small size and sound character of SRF-M95 (both use Toshiba TA2022AFN IC) and uses a single AAA battery too, but it has way better features such as a timer and alarm, a back up button battery for clock and presets settings, auto-preset, etc. Its belt-clip is better than that of M95 too. Therefore, if you can live with less sensitivity and want more features for your money, CR-LD120 is the one for you. The good news is, while SRF-M95 is only available in European market, you can easily find a CR-LD120 in a high-end A/V store like theGoodGuys or some online stores in USA. If you want a better sound and can live with something bulkier, then try the DT-110.
In order to simplify your choice further, I summarized above radios in the following table. Enjoy!
Notes about the table:
Price/Mods = The lowest price you can find/The price after modification
Sound/Mods = Sound quality/Sound Quality after modification - excellent, good and OK
Size/Weight = Like a cigarette case or a cigarette lighter/Mass
Batt/FM/AM=Battery used/FM battery life/AM battery life - hours
Sens/FM/AM=Reception (sensitivity & selectivity) /FM reception/AM reception - A, B, C, D
Tuner/Bass=Tuner type/Bass Boost
How to judge a radio?
Sensitivity - the more sensitive a radio is, the more stations it can tune into.
Selectivity - the ability to reject a nearby station. The more selective a radio is, the better it rejects the interference from nearby stations. However, too selective results in low-fi sound - narrow frequency response. For example, SRF-M35 sounds better especially on high frequency response than other Sony radios we discussed in this article. What you pay for the better sounding is the interference from a nearby station if that station is way stronger than the one you are tuning into. Overall, SRF-M35 has a right trade off between sound quality and selectivity - it sounds really good while is still selective enough to keep my favorite stations away from my evil local stations (it is a shame living in an university town that has no decent radio stations).
A tip for securing the Sony radio clips, see the picture below. With such a $2 pager stripper, I never drop my SRF-59 and M35 again.
[09/15/02] This picture shows inside a modified SRF-M35:
The two caps above the headphone jack are 220uF (output, originally 100uF); the big black cap on up-left of the volume thumbwheel is 330uF (power, originally 220uF); below it and close to the volume thumbwheel, are one 100uF (volume grounding, originally 10uF) and two 10uF (input, originally 2.2uF). These caps are all the ones in the signal path and critical to sound and thus are replaced with larger Panasonic caps (Panasonic caps are well known to be the best performance/price and they are small in size).
Copyright © 2005
Xin Feng Company